Put June update on my Pi3. All apparently fine including previous SMB shares after 20 minutes of testing.
Moved on to the VERO2, which was running the last May update. I had considerable trouble with the SMB shares after that update but, with help here, resolved them by adding new accounts to Windows10 to share. all now useable.
Following the June update last evening, on VIDEO files the SMB "WORKGROUP shares took about 1 minute of spinning “working” icon, to open to the list of computers with shares (my computer names). Choosing “XXX” (my computer name) took 2 minutes 41 seconds of frozen machine…with no spinning working icon… and opened my folder list ! Thereafter all appears fine.
Repeated this process three 3 times before making this report. Obviously not fatal but an irritating bug. (on the previous update these procedures took a second or two.