Conditional formatting (no borders; range B2:D5 in the example) is lost after saving the file.
Example: https://gofile.io/d/3AMBs3
Hi,
Please try again with the latest bugfix version from our BugFixes page or NuGet.
Does this solve your issue?
Regards,
Mario
Seems to be working 
Thank you!
Will a stable version with the fix be released soon?
Yes, it should be available before the end of this week.
Actually, some problems with conditional formatting still exist.
Example: https://gofile.io/d/VoKPlZ
Please, note the border line between the A and B columns in the example’s input and output files.
Hi,
Please try again with this bugfix:
https://www.gemboxsoftware.com/spreadsheet/nightlybuilds/GBS47v1184.zip
Or this NuGet package:
Install-Package GemBox.Spreadsheet -Version 47.0.1184-hotfix
Does this solve your issue?
Regards,
Mario
Yes, it does. Thank you!