Unfortunately, where I use the dock there is only a Wi-Fi connection. So I can’t say anything about LAN speeds. I copied an 8GB file from the WD7500BPKX via the USB 3 port and the transfer was around 88 MiB/s. However, the transfer itself froze twice for a few seconds, which didn’t happen when using the laptop’s built-in USB port (speeds were about the same). So it’s certainly not ideal…

OK, so today I was able to test the WD19TB dock again as I am back home. I changed the Thunderbolt security level to “No Security”, connected the dock to the USB-C port further away from the display and… it seems to work fine.
I’ve got two screens connected: 1080p 75Hz (DP) and 1080p 165Hz (but only works at 144Hz via HDMI, so it’s not a problem with the dock - same on PC with GTX1070); mouse and DAC via USB-A. I’m not sure what exactly caused the problems I had, but I guess it doesn’t matter much now :D
Thanks for your help @dingdongitsabear@lemmy.ml :)

I have a similar problem, but on Lemmy.zip (Lemmy.world looks fine). However, I am running Fedora Kinoite (immutable), where Firefox is not installed as Flatpak.

I’ve been using Fedora Kinoite for a few months now. Before that, I also hopped between different distros quite a bit, including Ubuntu, Mint, Fedora Workstation, openSUSE. To be honest, I really appreciate the immutable nature of Kinoite and maybe that is why I am really happy with the experience. Even “normal” Fedora Workstation caused a lot of problems during my usage and with Kinoite, nothing like that so far. So I can really recommend it.
There’s only one really small problem I’ve noticed, which is a problem with the rendering of some fonts on web pages (e.g. lemmy.zip). These fonts are not rendered correctly, or are replaced with some default fonts, and they just look weird. There was nothing like this in openSUSE KDE, so I assume the problem is with Kinoite itself, as I have this problem on two machines. However, it is so rare (I only noticed it on two websites) that it can be ignored.