How to increase logging for debugging of LDAP authentication setup?

[Fright]

I consider this "solved" for me, though I am willing to help test things if you want

thanks for sharing the results.
if the main problem is solved, then I suggest stopping at this. further research would be more convenient to carry out with access to the ldap server 
all the diagnostic additions mentioned in the topic except the last one have already been merged by @AdSchellevis. I will try to make a request to add the latter (with a timelimit diagnostic message).
Thanks again, imho the result is quite good additions to the tester page

[gromit]

Thank you for all your help, and I agree that more information in the "Tester" page is a welcome addition.