What I mean is - after over 9000 posts here, it is the first time I see this sort of confusion. So I would say that SuiteCRM’s logic for this is highly tested and should really work, and hasn’t been changed recently.
What I do frequently see here is people who think they have one thing configured and in reality have another, because PHP configurations are tricky, involve two PHP’s (CLI and web server), and sometimes hostings do weird things to php.ini files.
Hence my advice:
Let’s check if your configuration is effective in the way that you think it is. I am obviously not suspecting you, I am just trying to diagnose objectively and then we’ll take it from there.
Anyway, to answer your request for pointers, you could have a look in your config.php (dbconfig array), the same in config_override, if present, and you can see the code at these places
Good luck, and tell us what you find. Thanks.