Cannot mount remote USB drive over network after installing network switch My previous home network setup was MBP into the single GbE port on my wireless router, a Mac mini into the 10/100 port. Both talked perfectly to each other - both are running 10.15.7
The Mac mini has an external USB drive called Media 2, and I could mount and use it over the network via the MBP.
Today I installed a GbE switch so that both Macs can talk to the GbE port on the router, and now I can't mount the Media 2 drive on the MBP any more. Everything else works, it's just that external USB drive that I can't mount on the MBP over the network.
I get this box every time:

I can connect to the Mac mini using screen sharing and access Media 2 on the MBP that way. While I'm screen sharing the mini via the MBP, I can copy from Media 2 to the MBP. I just can't mount Media 2 directly on the MBP.
I've Googled around, and the most common solutions - restart the Finder or log out/back in - haven't worked.
Any suggestions gratefully received!
It fixed itself after 3 days. Seemingly it was a permissions issue that coincided with my adding the switch, but I have no idea how or why it suddenly decided to start mounting normally again.