Unable to connect to Synology NAS on Wi-Fi despite being able to ping?

Wondering if anyone can help, as this problem is driving me a bit mad and I can't seem to find the issue. I have also posted this in the Eero subreddit, but despite the very helpful advice from a redditor, I'm still at a loss.

TL/DR: I am unable to connect to my Synology NAS (DS920+ running DSM 7.1.1-42962 Update 4) via my MacBook Pro when the laptop is on wifi, but it's fine when wired via ethernet. Here is my set up in ascending connections:

ZTE 5G Modem in Bridge Mode>Eero Router>Netgear 4 port switcher>Synology NAS

The NAS is connect via ethernet and DHCP with an address of 192.168.7.150.

The laptop is connected via Wifi and DHCP with an address of 192.168.7.151.

I can see the MAC addresses on both the Eero app and relative devices.

I have ports 5000/5001 opened on the NAS via UPnP which are showing as OK when tested.

When I connect my laptop to the switcher, I can connect to the NAS perfectly fine. I can also connect to the NAS via Quickconnect. When I try and load 192.168.7.150:5000 in a browser (have tried both Safari and Chrome), something starts to load, but nothing appears.

I can also ping the IP from Terminal and get a response.

I did think there might an issue between the switcher and the Eero, although I have just replaced the switcher to check if the old switcher caused an issue, but this has not solved things.

I have also hard reset the Eero network (the main puck and two others) but this did not help.

My question is - is there something on the NAS or Eeros' settings which I have missed that would cause a block between wifi and ethernet based devices?

I realise this might not be a specific Synology issue, but having gone through everything with Synology, they suggested the cause might lie with Eero. This only started happening a few weeks ago, so maybe an update shifted something along the way?

Thanks in advance!