Hello!
Thank your for your bug report! Unfortunatly the save you have uploaded seems corrucpted and can't be unzipped, could you try to send it again.
We have investigate the issue on other save and the Combat Strength bonus seems to be applied, could you also send a screenshot of your Unit's Combat Strength?
As the title says; I have the hero badge, which should give my units a combat bonus, but it does not.
Note that the zip folder created by the in-game bug report feature was too large to upload, so I just uploaded what I believe should be the most recent save.