My late fee is $100 after the 5th, and a notice to gtfo (pay or quit) three days after that. I’ve never had to actually serve the gtfo order, but I have had a tenant pay the $100 before. They were never late again after that.
I also asked them why they were late, they were college kids that “just like totally forgot man”, so I started sending them a reminder text every month on the 4th.
Anyways, I think your fee might be a little lenient, but there’s nothing you can do about it until the release renews. In the meantime, I’ll echo the others that you should probably try to find out the reason why they’re late. Reminders don’t hurt either.