I entered Portugal last week with a brand new UK passport. I tried to use the e-gates but they weren’t working so had to go to an immigration desk.

When I left a week Later tthe e-gates were once again not working (it’s not only LHR then) and the officer at the desk spent some time leafing back and forward through my passport and then asked where the entry stamp was. I just shrugged my shoulders so she stamped it for exit anyway.

I’ve since checked several times and there’s definitely no entry stamp.