illegal mix of collations

PHPMaker General Discussion (PHPMaker)
1

When I try to edit my table list I got this failure:
Failed to execute SQL. Error: Illegal mix of collations (utf8mb4_unicode_ci,COERCIBLE) and (utf8mb4_general_ci,COERCIBLE) for operation ‘=’ (1267)

All varchar colums and the table itself have this collation: utf8mb4_general_ci.

What is wrong ?

2

I changed the HTML charset to: unicode utf8 and now it is working without failure.