So I started having this issue in v-6.5.2 and upgrading to 6.6 has not solved it

So I always use folders to organize my songs and it was working fine until recently (not sure if started as soon as I upgraded to 6.5.2 but did notice it recently when using 6.5.2 and I have since upgraded 6.6 and still having the problem
Which is
For creating any new songs even thought I have -- "Link expansion and visibility in folders "checked " and then create a bus channel in the mixer , audio tracks in folders works as expected in the Mix/console window
But if I make instrument tracks in a folder it works in the arrange window as expected (expand and collapse ) but the associated Bus channel in the mixer shows and clicking the folder icon will expand and collapse the folder in the arrange window BUT it will not expand the tracks in the mix window ????????? ANY body know if there is some additional thing to set OR is this a bug ?