You haven’t included any system info so I’m guessing, but are you running an rc version of the 7 kernel?
udev-usb-sync and kernel 7.0-rc
If you experience slow transfers to USB attached disks, remove the package
udev-usb-sync. It is not known why the 7.0-rc kernel causes this. There may be a regression of some sort. Awaiting the final release of the 7.0 kernel before jumping to conclusions.See [Unstable Update] April 2026 thread for more info