Created attachment 203945 [details]
Example file from Excel 2016

Attached XLS example file has a simple IF function, which returns with a FALSE value, as the condition is not met and there is no alternative value specified.

This is displayed as 0, instead of FALSE boolean value. If the file is saved as XLSX in Excel, then the display in Calc is correct.

1. Open attached file
-> Values in B4:B5 are 0 instead of FALSE

2. Open the second attachment
-> Values in B4:B5 are FALSE like in Excel

Version: 26.2.0.0.alpha0+ (X86_64) / LibreOffice Community
Build ID: 620(Build:0)
CPU threads: 16; OS: Windows 10 X86_64 (build 19045); UI render: Skia/Raster; VCL: win
Locale: en-US (hu_HU); UI: en-US
Calc: threaded

The xlsx version seems to look good since 7.3 commit:

commit e4f76cd9a4814ce6cc4795e5e1a5c74d54cb7513
Author: Justin Luth <justin_luth@sil.org>
Date:   Wed Feb 23 10:34:29 2022 +0200

    tdf#122098 xlsx im/export: let formulas guess their number format