Thanks for posting this! I was about to do the same. Our team is experiencing the same issue (using Chrome, haven't tried other browsers) and it's terribly frustrating.
Did you actually "raise a ticket"?
I raised a ticket, only to receive a prompt response, kind and helpful moreover. Tl;dr: it's a known problem, and it is resolved in CM to 6.3.0 - although if you don't mind putting your password in manually every time, you can just remove the autocomplete from this site and continue using the older version of CM. Below is the response from Cloudera:
Thanks for contacting Cloudera. My name is Ela and I'm happy to assist you with this case.
As per the case comments, I understand that the user name is automatically added to the table search in HUE web UI.
Please be informed that this issue mainly occurs when the customers saved their passwords in their chrome browsers and hence they are getting the USER NAME in the search box when they logged in with HUE.
This issue is a known bug in chrome browser, so I am linking this case to the existing JIRA CDH-78170 and this was fixed permanently in the newer CM version 6.3.0.
CDH-78170 - Chrome password autofill will populate username in hue sidebar search box
Temporary workaround: Click the chrome web browser —> Click the profile photo -> passwords -> under section "Saved Passwords", find the hue website address and remove this entry.
Permanent fix: Please migrate the CM version to CM 6.3.0 for the permanent fix.
Kindly revert back for any other issues/clarifications required.
Note: Since P4 is reserved only for future requests, I am increasing this case priority from P4 to P3. Regards, Ela"