Using Enpass extension 6.5.1 for Mozilla Firefox 82.0.2 (64 bit) on Windows 10; Enpass desktop version 6.4.1 (643).
I logged into a website which I hadn't visited in a very long time; its login was not in Enpass but was in Firefox Sync. I logged in and was told to change my password, which I attempted to do using Enpass. It should be noted that this company does have a support forum for users which I do occasionally visit on a subdomain (forum.xyzcorp.com as opposed to simply xyzcorp.com). This login was in Enpass, and the two logins although on the same root domain do use separate user IDs and passwords.
I generated a password and updated my information in the website. Firefox Sync popped up a window asking if I wanted to update the password, but before I could react (about a quarter of a second) the Enpass extension popped up, erased Firefox Sync, and asked me to update the password for the support forum. There was no option and no way to add a new item with the password which I had just updated. So now I have lost the password and have to go through the whole hassle of having my password reset again by xyzcorp.
You really should fix this problem, it's caused me grief a number of times before. Firefox has a pretty good password manager and the Enpass app should not block it out when a site is updated. There should be an option to add a new login/web site with any request to update a password. Or, preferably, both.