Not natted port problem

[pippo1993]

Hi, I recently installed an OPNsense firewall where I have configured many ports .... almost all Natted (eg 123456 ext -> 654321 int) working perfectly unless the usual port 80. However, I get a problem ... This does not come out of the gateway of my network provider ... while if I accidentally make a NAT out perfectly.

EXAMPLE:
80 -> 80  Don’t work
345 -> 80 Work

What could it be?

Hope you can give me a hand.

Thank you