When TG was updated automatically to V4.0.0.2 I got the message -
"No support incognito mode, please disable incognito mode for add-on"

I checked the TG add-on option "Don't Allow" for "Run in Private Windows" and restarted FF.

I then got the following page -
"Welcome to Simple Tab Groups v4
Please enable "Restore previous session" in browser settings:"

I checked the box "Restore previous session".

I also noticed that all my tabs disappeared from every tab group. I restored them using a backup and restarted FF.

I again got the following page -

"Welcome to Simple Tab Groups v4
Please enable "Restore previous session" in browser settings:"

even though the "Restore previous session" was already checked.

Every time FF v68.0 starts up, the

"Welcome to Simple Tab Groups v4
Please enable "Restore previous session" in browser settings:"

page is displayed even though the "Restore previous session" box is checked.

I reverted back to v.3.4.4. I have also turned off "automatic update". This is not a good rollout.