WiFi as WAN speed vs. direct WiFi connection

Hey there; I just received my Max Transit Cat12 this week and set it up in my house before taking it out on the road.

Specifically when using WiFi as WAN, I am seeing a few unexpected results.

When I am have only my home 5GHz connection as priority 1, I see this:

When I have both 2.4 and 5GHz as priority 1, I see this:

When I am connected directly to my home router (without the peplink in the mix,) I get this:

I know that speed tests can vary based on outside influences, but these were all taken moments apart without moving any of the hardware, and the numbers are in the same ballpark each day that I’ve played with this.

I guess what I’m asking is what kind of behavior / performance should I see when using wifi as wan? If it caps out at 40mbit in either direction, that’s fine, but if it’s going to give me only 10-15% of the main connection’s speed, then that is something different.

Thanks in advance!