mix console / master bus mute issue

Not sure if this is version specific but I’m just noticing it now in current 9.5.30

(In mix console) When I have tracks muted in a project then mute the master then un-mute it ALL the tracks become unmuted.
This can’t be the expected behavior, correct?
(Also soloing tracks can behave whacky too sometimes, un-soling doesn’t always work as expected or go back to the previous state.)

That is normal behavior, don’t mute the master use the control room for that.

Thanks, it also happens on group channels too (eg a 2 bus routed to the master.) So using the mute on a group channel will un-mute all & any muted tracks. Is this normal as well?

Yes it is, I would encourage you to try the Listen function instead.