All Firefox passwords gone after using Avast Passwords

[isark]

I just installed Avast Passwords and during installation I managed to link it to both Chrome and Firefox.
After the installation I kept seeing this error:

Pressing the button does nothing, even though Firefox is definitely closed (tried restarting).
After going into the settings and trying to again manually import my passwords through Firefox, it gives me an error that there ARE NO passwords in Firefox.

I then go into Firefox and see that in fact all my passwords are gone!
Also Firefox keeps asking me to reconnect to my Firefox account in order to sync.
I found online that AVG and Avast can cause that but I would be able to still recover my passwords through a file called logins.json.
When I go into my profile folder I see no such file. The article said the file would be changed to something like logins.json.corrupted but I still don't see anything!
My Chrome passwords are intact inside the browser.
I also have this enabled:

Does anyone have any idea how I can fix this?

Follow up:
Firefox still doesn't show my passwords but now there is only one login and password available and it's this:

Only now the logins.json file is visible but it's only 2KB and most probably includes ONLY the abovementioned login. I can't seem to understand where my other 500 logins went!

[isark]

UPDATE:
I have determined that every time I try to click this button:

all the logins from Firefox disappear and then I have to log in again the next time I start it up.
It's not a big step forward but at least I know what's causing it now.
I am assuming the deleted logins from the first time are irreversible at this point.
Does anyone know what might be causing this?

[Pavel Studený]

Hi, the import from Firefox also removes the passwords from the browser, so that Avast Passwords and Firefox do not conflict. The process of putting the passwords back to Firefox is not very straightforward, but it should work for you: https://support.avast.com/en-eu/article/Export-Mozilla-Firefox-Passwords-data. However, if you add the Avast Passwords extension to Firefox, you should not need to do that.

[isark]

Hi, the import from Firefox also removes the passwords from the browser, so that Avast Passwords and Firefox do not conflict. The process of putting the passwords back to Firefox is not very straightforward, but it should work for you: https://support.avast.com/en-eu/article/Export-Mozilla-Firefox-Passwords-data. However, if you add the Avast Passwords extension to Firefox, you should not need to do that.

Thank you very much for your reply. Now it makes sense why Avast would remove my passwords from inside the browser itself, especially since I can still save passwords to the browser itself and then it would make Avast Passwords redundant in the first place, because they are not protected in any way. I really appreciate the article you shared and I will try to recreate the process myself. However, I am still confused as to why Avast Passwords doesn't do the same for Chrome, as I still have all my passwords there!
Cheers!