I was missing a meta.xml file in one of the GIT branches and when I merged into master the class was added but not the meta-xml file.
In a new scratch org I attempted to do a PUSH or the merged metadata but IC just said "All Files Up To Date"
When I wen into the terminal and tried to push, it showed me the error.
Upon getting the missing meta-xml IC happily pushed.
So the issue is when SFDX reports an error on a PUSH IC simply says all files up to date. It took me a few to figure out that there was actually an error and manually rectify it..