Some sites don't open in the UDP protocol

hello
I am participating in this forum for the first time, and I may be wrong, I hope you will forgive me for my boldness.

My problem is that I have two routers and I tunneled them together using the Vxlan tunnel and the connection is there
The problem is, I hit the Open VPN protocols of the TCP type and I am facing a slow speed
But it unlocks everything without problems
So I launched the IKEv2 protocol, which is of the udp type, and I saw a high speed and it was of good quality, but the problem is that it does not open some sites!
Like YouTube! I asked some colleagues to suggest that I change MTU, but with this change, nothing changed and it didn’t work!
I wanted to know what it is without your suggestion and how can I fix this problem in UDP I wanted to know what it is without your suggestion and how can I fix this problem in UDP?

Hi there, can you post your configs?

Please enclose them in code tags for readability.