From about two or three weeks ago, I found that whenever I start Firefox and connect to VPN, it is fast for the first 5 minutes then becomes terribly slow beyond, and it happens very constantly. There is not the same problem on Chrome. I've contacted with the support service but no suggestions help (request #4257080). I believe it is the problem of the Firefox extension itself.

(update 2023/1/30)
It seems the problem has been fixed.

(update 2023/2/1)
Nah... problem's back, disappointed. I'm gonna use another VPN.

It worked just fine and recently(2023/1) the speed is down to like 56k modem connection. Reported this issue to the customer service and the answer I've got is "Sorry, there is no fix for extensions" And all I can do is just to endure this until I give up or pray for things going well. GJ Surfshark.
以前都正常運作但最近(2023/1)慢到簡直要吃屎，去跟客服說得到的答案是抱歉這插件沒修復方法。所以我只能忍耐。使用這之前請三思
この前に問題なく使ってたが最近(2023/1)のネットスピードはくそくらい遅くなったのでカスタマーサービスと連絡したら「すみません、修復の方法はない。」と言われた。我慢しかないと同然の答えに呆れてどうしようもないの自分がここにいる。このアプリを使う前によく考えないと痛い目にあうよ。

update! still not working on firefox!!! boooooo! horrible. it was such a great vpn. The Firefox extension is broken. The VPN service works correctly on the desktop app and other browsers, but on Firefox the speeds are horrendous and there are frequent errors (proxy authentication error, not logged in error when logged in, general unresponsiveness.)

The Firefox extension is broken. The VPN service works correctly on the desktop app and other browsers, but on Firefox the speeds are horrendous and there are frequent errors (proxy authentication error, not logged in error when logged in, general unresponsiveness.)

Не работает в РФ, верните деньги за подписку на 2 года. Проблема массовая, набрали денег и теперь занимаются отписками, проблему не решают.

Internet connection is so slow when VPN is used, but it works perfectly fine on Edge so please fix it on firefox please.

The worst update ever!!! Proxy error all the time....

Не работает в РФ от слова "совсем", где-то примерно как месяца два. Поддержка морозится, говорят устанавливать только отдельно на устройство и будет работать. По ходу, расширение накрыл РКН, т.к. ближайший для России сервер был сначала в Грузии, а потом стал в Украине. Делайте выводы. Не рекомендую к установке. Средства не вернуть уже.

Dosn't work as an extension, even can't login

I JUST WONDERED How a person would be crazy to creat app that their website is filtered, so how i shoud creat account ?
dosnt work in iran

non capisco perchè non sono presenti versioni aggiornate, dato che dal sito ufficiale dovrebbe far scaricare la 3.18. Tra l'altro avevo scaricato la 3.17 ma ora è scomparsa

没用

Not useful in China

Too lazy to register.

should've listened to the reviews. this might be the worst VPN in existence. to anyone considering surfshark: DON'T DO IT! you'd be lucky to get a connection 50% of the time. "proxy connection error" should be surfshark's tagline. what a waste of money.

Unusable, keeps disconnecting every few minutes. Even when connected, pages don't load or load extremely slowly

Only on Firefox, fine on Chrome

The new update sucks. Stop trying to do everything. I don't need your ad blocker/popup blocker/data breech alert/malware alert nonsense. I have other stuff for that, and historically, you do not do a good job at working cooperatively with other programs.

And now, instead of a quick click to turn on the VPN in my browser, I have to do multiple clicks to turn that on because you're trying to push this new trash on your users. I just want the VPN. That's what I'm paying for. The fact that you're pushing your other nonsense SO HARD at the expense of you know, the actual VPN services is absolutely ridiculous.

(Updated in 2022/11/14) This addon is still very terribly unstable. I'm living in Taiwan, and network environment is quite speedy when without VPN, but after enabling Surfshark VPN in Firefox, the experience becomes a nightmare: the network often becomes very slow (Even though the servers I selected shows the loading are quite low, < 25%), or unexpected disconnection and shows some unreasonable error message (for example, it often shows "your subscription is expired", but my subscription should be expired in 2023/06). Whenever I encounter such problem, what I only can do is restarting Firefox, this is the only addon I'm using with the most ridiculous quality.

If you rate 1 star to this addon, no matter how detailed is your issue description in this review, they always reply and ask you to contact their supporter via live chat or email, but if you really do contact with their support, the only thing they are going to do is to merely ask you to reinstall the addon and try again, and you will find nothing improved at all. LOL.

(Updated in 2022/04/14: In 2022/03/01, the reply from developer ask me contact to their Customer Support via Email, and they ask me to reinstalling the addon. So I reinstalled, however this doesn't solve the problem at all. It just logged out immediately when I click on addon's icon in 2022/04/14. Ridiculous. ) This addon may suitable for some unimportant tasks such as watching Netflix, BUT this is DEFINITELY NOT SAFE for sensitive data. Because this addon gets red text "error" in the popup UI frequently and cannot work at all until I restart my Firefox, sometime I have to restart my Firefox more than 5 times in a day. // THE TERRIBLY WORST PART IS: sometimes, when mouse hovering on the toolbar icon, it shows colored "connected" so I feel easy to work. But occasionally when I click the toolbar icon... I was astonished to find that I am totally logged-out, without any sign?! (and the toolbar icon became to gray immediately), I even donno when it logged out. What the hell is this stability for a service focused on "Security"? You even cannot make a average-degree stable addon. I have never used any other addon is unstable like half of this one in recent 10 years.