Log-in Mystery

site-compatibility-investigate
#1

This is the link to my router software: http://tplinkwifi.net/webpages/login.html?t=1528724027141 .
When I access it, Kee recognizes the site and inserts my userid and password, but I cannot log on.

After some tedious testing to find out which extension was preventing the log-in (which works in Edge), I found that I can expose the actual password on the log-in page, so I copied it into Word Perfect, along with a copy of the password as entered in KeyPass. The two entries in WP are identical.

I then found that, if before I try to log-in, if I expose the text of the password, cut it and paste it back in, I can log in. Finally, I tried creating an auto-type entry, but that will not insert the password.

Seems rather odd to me; any ideas?