I noticed that i couldn't receive sms on a LTE mikrotik device.

disabling default firewall did help, and i can receive sms.

how to unblock incoming sms on LTE device in default Mikrotik firewall rules ?

would this be a good rule ?
it looks like it works

I must be missing something. I cannot see how receiving SMSes should be related to IP firewall at all. So I'd expect some problem at operator's SMSC whose resolution was correlated with your changes of the firewall.

The rule you have shown accepts IP packets that contain a string "sms" somewhere in their payload.

Yes , i was thinking the same.

i double checked today, and found receiving sms does work also without my added rule. ( which indeed did not show any packets count et )

so in the end i probably was some sort of problem in the settings or software.

disabling/enabling complete firewall rules did something and i can receive sms.

Ros v6.47.1 on LHG R

SMS handling is completely unrelated to IP firewall. The SMSes come and leave via a data channel between the router and the modem which has nothing to do with the router's IP stack.