I think you mean that your AP and computer are wired by ethernet not fiber, that router does not support SFP+ so its not possible to be a fiber connection. From your updated comments for a budget AC Wave 2 wifi router that speed seems acceptable, you can try to increase your channel width and see if that helps but if there’s a lot of interference from neighbors then that will be the speed you get.
if you can please hook up a laptop directly to your ISP Modem/ONT and run a speed test, this sounds like one of your cables are damaged forcing it to negitiate at 100mbps instead of gigabit.
you see that on one side there a bunch of purple cables not connected to anything and only a few are connected to the green cables from your router? you need to install a switch and hook all of the purple cables up.
Each of the purple cables on the right is a cable going to one of your rooms and the only ones hooked up are the ones connected to green cables from your router. The lights being off just means its not currently active/being used on the other side, it looks like you have 3 outlets hooked up right now.
This is as much as they can see if you’re router even has deep packet inspection https://imgur.com/a/R4MzGNV
In Canada there were a few good years when Telus gave us fiber internet through a Nokia GPON ONT SFP+ module, which we could plug directly into a SFP+ router and ignore all of the ISP equipment, thoses were the days, now they moved to XGS-PON and we have to user their network hub since the XGS-PON module doesnt have onboard registration hardware :(