i think i understand what other users meant;
first, it only starts translating when highlighting then you hover over the highlighted text and by doing this, this will open a deepl website where the highlighted text will transfer to get translated then the translated text then gets back to the floating cloud/comment in which the translated text will be placed. what annoys people is the opening of deepl website and the blinking of the webpage (although this is a que for transferring data to each site, for me its ok but for other people who has epilepsy are fked).
second, i usually use double click to highlight all text inline rather than using dragging and because of this, some text were not transferred correctly to deepl (the highlighted text contain both english and japanese text). that is why other users experience sometimes blank or in my case incomplete text to be sent in the deepl website.

it seems you are not using an api for deepl for this in order to bypass the quota but in the expense of user experience.

this guy "To Google Translate by Juan Escobar" is my usual guy i use but since i want deepl and he has the same style as you but uses google's api thus will lead to quota but still faster and more responsive. the reason why this guy got less star reviews is because people don't check option and the option he use as a default is shit in my opinion

use deepl's api, it has quota but for better user experience.

edit: also discovered that special characters will remove other text thus leaving it blank (eg. 【 】)