NAT type C using EP06E and Nintendo Switch

I have an EP06E installed in my router running Openwrt 19 and I can’t use the online connection on my Nintendo Switch because it reports the NAT type as C. However, if I connect an android hotspot with the same APN and sim card, I get type B. Any ideas on how to solve the issue?

EDIT: I should add that the APN on my cellular connection gives me a public IP and it’s not under CG-NAT.

Thanks for your query in Quectel forums.
Can you take a screenshot of the problem phenomenon,thanks.