Re: SuperUser login disables most plugins
Technically the superuser/superadmin doesn’t log in to BP but to WP.
Not heard of this happening before, as for debugging, generally that is a case of reducing a setup back down to basics to finding a working state then re-introducing elements checking each time until an issue is replicated; in this instance you might start by disabling plugins one by one and check each time whether the issue still manifests, If you’re using a custom theme it might be wise to drop back to the BP default theme just to ensure that the custom theme plays no part in the problem.
If the issue is unresolvable and you need further assistance please post full details of your setup.