MTU different size by packet type?

Hi,

So I was troubleshooting some Access points which were failing to go online (state config failed). It turned out to be a middle device which fragmented the packets between the Controller and the Access Points. Everything clear so far.

Now, what is strange is that ICMP-ping with size 1500 was ok, but UDP-ping 1500 was not ok. So because CAPWAP use UDP, the APs failed to go online.

My questions is: is it possible for a device to have different MTU sizes (ICMP packets pass through, but UDP packets of the same size failed)?

Another explanation could be that UDP-ping (which is in fact "capwap ping" command) use larger packet head, so this would explain why ICMP is ok and UDP nok.