Initial situation
We have a contribution page to purchase a membership. A profile is used to collect address data. Furthermore, this profile is configured to also create a Wordpress user account: The user can enter a Wordpress user name and also check its availability. And the user can enter the desired password in the two boxes.
The issue
Until recently, everything was working as expected. Upon confirming the contribution, the Wordpress user was created with the given name and the user was automatically logged into this account at the end of the transaction.
Now we have a changed behavior: The transaction completes without any error, but the user is not automatically logged into the newly created account any more. It is NOT possible to log into the account with the entered username and password. In Wordpress, a new user is created, but not with the entered user name. The username is instead derived from the address information (e.g. mr-frank-smith) and an unknown password is assigned. So the user has to use his e-mail address for login and initially he has to go the "forgot password" route to request a new, known password.
System information
CiviCRM 5.34, but the behavior was probably also present with 5.32.
Wordpress 5.6.2 with the most recent Member Sync and Profile Sync plugins.
Additional Information
Setting up just a page with a profile to enter an e-mail address and create a Wordpress account does work as expected. Upon completion of the form, the account gets created with the given username and the user is automatically logged into the account.
So, somehow the problematic behavior is linked to the contribution page/signup process.
I tried it with the Stripe payment processor as well as with the dummy processor and the issue occurred in both cases - so it is probably not related to a particular payment processor.
The Question
Can this changed behavior also be observed on other installations? Wondering, if some settings etc. might interfere. If this is a known issue: Are there any good workarounds? Asking new members to request a new password after they entered one during sign-up is not so ideal...
Edit: Further investigation
On a newly created virtual server I set up the lastest Wordpress without any plugins and also the latest CiviCRM (5.34) without any plugins. I experience the same behavior:
A profile with settings to create a Wordpress account does create this account, if it is used standalone on a page. If it is used on a contribution page, the Wordpress account does not get created. Seems to be a bug most likely introduced in one of the latest versions of CiviCRM.
