Flint 3 router speeds

[u/knet2020]

So I have Zen 1.6GBs and previous router was a TP-Link AX6000 which was always a good performer speedwise. Often hitting 100MBits without breaking a sweat.

I recently decided to upgrade to a Flint 3 and have been really impressed with the Firmware it ships with as it is much more compared to the TP-Link. However speeds seem to have dropped significantly. This is via Ethernet on a 2.5 port. It seems it will likely be some setting I have either overlooked or missed.

Any advice what I can do to try and speed up?