I have been having this problem too. I have tried to resolve it by
copy/pasting my data on to new spreadsheets, where the autofilter works
for a while and then freezes up again. I have been using filters for
years without problem and only encountered this problem in the last few
weeks.
When I click on the drop-down, it does not bring up the list, so I
can’t change the filter selection. Likewise I can’t use the filters on
any of the other columns.
If I use “data / filter / un-click Autofilter”, the drop-down boxes
disappear, but the rows remain hidden. I have to the use “format / rows
/ unhide” to get them back again.
And I don't have any blank rows / named cells etc.
Sorry this isn't an answer, just another instance of the problem.