I was running R80.20 with JHFA183, did an inline upgrade to R80.40 (then installed JHFA91) which all worked, but the layer 2 configurations on the bond completely broke, three TAC engineers involved so far, not one of them from Israel.
Reverting back to R80.20, the first node took 1hr and 40 mins to revert, the second one rebooted at this time point but is just sitting there at "Starting the system".
Personal think the level of support and experience out of TAC centre the UK is directed is not reflected in the premium price we are paying.