Your explanation was fine. I just jumped to confusions. :-)

However, what I theorized might still be reasonable. By linking the
combobox and the cell at object level, you're creating a pretty strong bond.
My feeling is that this bond would transcend anything you could do in VBA.
I also theorize that the bond itself would make use of events to keep itself
up-to-date. So it may just not be listening to you.

OTOH. You're changing the cell, which will cause the combobox to change.
But when does it change? It might be that it holds off on that change until
you finish what you're doing. (Or it even might simply wait for you to
enable the interrupts again.) In both of those scenarios, the delayed
response will mean that interrupts will be active again before it happens.
But also that setting/unsetting any sort of "ignore" flag would possibly not
work either.