Created attachment 198801 [details] XLSX Open XLSX and see colored filter but nothing excluded. In MSO it has filter set to exclude blanks and LO really shows so, but in autofilter there are no Blanks. And ronudtripped file is not opening in Excel. There was change in LO 25.2 with bug 163842 for the part of rRT, but this was also NOK before the commit, as seen in fileopen. Saved file would open in Excel looking good, but autofilter selection was inverted, only Blanks marked and filled values not. Also NOK before original commit in LO 7.1.
With LO shows in 'filter by condition' 'standard filter': Nachnahme is not empty. Which is not visible directly in the primary Autofilter window.
In the list should be (empty). And there is bug when saving and opening in MSO. I do not see how 'filter by condition' would affect this. When opening menu, Empty seems blue, but that is not marked, rather offered as selection, as moving mouse down similarly sets other itens as blue. So using that seems a separate issue. Writing this as ticket is not confired, so I understood the previous comment not as addition but as question.
For roundtripped file is not opening in Excel, fix is 641fd154649edfb3fe1dad89f833f2e48caf41d7 in https://gerrit.libreoffice.org/c/core/+/181344
After the RT fix, I see the following: - original file opens in Excel with 4 items checked and Blanks not checked so next row seen is 301 - it opens in LO as expected with next row seen 301, but in the filter there is 0 checked, instead of Blanks unchecked (click once no change, twice rows are seen, but with 0 checked) - RT file in Excel opens as expected but with wrong inverted filter, items are unchecked but Blanks are checked. We may close this one for RT but I would rather keep it for filter, as RT is clear and resolved.