I bumped to the Hub4 and Gig1 a few weeks ago - I asked about Hub5 and was told it's not in general release yet but Gig1 customers will be the first to be upgraded (presumably since Gig1 is actually 1.2Gbps, so can make use of the new 2.5Gbps WAN port).
Happy to help if you want to test any Hub4...
I've just had a similar issue with my setup - RT-AX88U main router with RT-AX56U AIMesh node. My main PC (connected via CAT5 to the node) could no longer access shared folders or Plex from my Windows server connected to the main router. I could ping the IP address OK and access various Hyper-V...