Delta in speed for WAN vs LAN on WiFi

Excuse the title if it isn't using perfect terms, but I have an interesting phenomenon that I am trying to make sense of on my network. I've recently upgraded to 802.11ax 4x4 gear and am seeing excellent performance when wireless clients are download/uploading files to a Synology disk-station on the same LAN segment.

However, when those same wireless clients attempt to download/upload things to the greater internet performance is worse. Note: My internet speed is gigabit

What is more confusing is that I can validate on the same switch port that devices can indeed get gigabit download/upload speed on a wired connection.

To clarify here is a rough diagram:

Wireless:

M1 MacBook Pro (10.0.1.90 ) <------------ 920Mbps/870Mbps -------------> Synology (10.0.1.27)

M1 MacBook Pro (10.0.1.90 ) <------------ 620Mbps/510Mbps -------------> Internet

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Wired:

M1 MacBook Pro (10.0.1.120 ) <------------ 980Mbps/980Mbps -------------> Synology (10.0.1.27)

M1 MacBook Pro (10.0.1.120 ) <------------ 920Mbps/920Mbps -------------> Internet

I've tested the above with various speed tests online, hell I even stood up a server in a nearby datacenter and ran iperf tests to be absolutely sure, but regardless of the testing methodology wireless speeds tend to cap out around 620Mbps when going over the internet while wireless speeds to the local Synology sticks around 850-920Mbps.