I have more of an infrastructure or javascript issue. I often find myself on a map like this until at some point seconds later all tiles render. I think something is blocking the rendering.
I am in Switzerland on 10gbits internet on a beefy new Mac Studio on the latest Firefox Nightly on a 4K screen. There should be really no bottleneck.
As a small reference, Protomaps on Maplibre doesn’t have that issue.