boot camp is not showing "start with mac"

If you reboot and hold Alt/Option, do you see macOS as a selection? If yes, select and test.

Switch between Windows and macOS in macOS High Sierra - Apple Support

From macOS Terminal, post the output of

diskutil list

diskutil apfs list

If you have Mojave, your storage was converted from CoreStorage and/or HFS+ to APFS. If you have a Fusion drive, it was converted to an APFS Fusion Container. For a 2013 Mac, there are no new BC drivers to allow bootcamp.exe to get to the APFS information, hence it does not show in the BC Control Panel. The driver is capable of seeing HFS+ (or a CS/HFS+). There are third-party drivers that allow APFS visibility from Windows, but Caveat Emptor !

What is the current version of macOS and the year/model of your Mac (do not post the serial number of your Mac)?

iMac (21.5-inch, Late 2013) running on MacOs Mojave and on bootcamp I'm using Windows 10. This problem started when I upgraded my mac to Mojave and haven't done any updates on windows the after mac update.

I can boot to mac this way but is there a way to repair the bootcamp app on windows to a way it used to be?

Just checked Disk Utility and like you've said my HFS+ was converted to APFS. Since I can't trust windows with my OS I will stick to using it this way. Thank you for your time.

If you want to be adventurous, see when are boot camp drivers going to be updated ? .