I’ve been having the same issue as everyone else in this thread. I was finally able to reset it through the eufylife website AND login to eufy security. This worked for about 24 hours and then my password “magically” stopped working again.
As a point of reference, I had trouble setting up my account initially. It took me several tries to be able to log into both eufylife AND mysecurity.eufylife. One of the three people I invited into the app (to watch the doorbell and get alerts) also had this problem.
I was hoping the solution @mitch14 found (no special characters in password) would work for me. Alas, it did not. I will continue to look for a solution (still no response from the Eufy ticket I opened via support@eufylife.com), and update this post if I find one.
I am using my eufy 2k wireless doorbell with the very awesome Home Assistant (hass.io), so it is possible this has something to do with my password being reset (however unlikely this may be). I really like my doorbell camera, and I’d like to buy more security cameras from Anker/Eufy, but this is a big problem.
Anker, please take action to resolve this issue, and work with the Home Assistant community to better integrate your products for the home automation enthusiasts in the world (there are many).