It's probably different where you're located, but around here it's pretty much a given that an engineer will work more hours than what is written in the employm

It's probably different where you're located, but around here it's pretty much a given that an engineer will work more hours than what is written in the employment contract, even if they regularly come in late / leave early / WFH. Imho flexible hours are a good thing as they remove the pressure to stay around doing nothing until late because you can't be seen leaving before 7pm.