The first thing to check is that Tidal is supported in your country. You can see that here:
If your country isn’t on the list, the likelihood is that there is a speed bottleneck between Tidal’s servers and your Internet Service Provider.
The data will have to take a different route through the internet when streaming to your Network Bridge compared to going to your PC (they both use different mechanisms to get the data) so one of them working doesn’t really tell us much about what is happening with the other one.
Unfortunately if Tidal is unsupported in a particular region, there isn’t anything we can do to resolve that. It will cause some unpredictable behaviour, such as dropouts in the stream through certain devices.