Bypass MAC in Hotspot sometimes not working...?

Hello, I am confused… I have placed shellys for measuring inside our public hotspot. To comunicate with them, I bypassed the mac by Ip Binding. But in the moment, I can reach some shellys. But some shellys I cannot reached. It seems, that the hotspot dont let them thru…

It seems, that the adding an IP Binding sometimes work and sometimes not… How can I check, if everything is configured correct or which parts of the configuration went wrong? (For example if all firewall rules are ok…)?