I'm using xDebug with PHPStorm + Docker container with ubuntu 16.04 + nginx + php. It always worked as expected.
Recently it stopped working. I don't know if I upgraded any software which could have caused this issues. I rebuild the docker image from time to time, but recently I only did very minor changes to the dockerfile - does not seem like that's the source of the problem.
Description of the actual issue:
After stopping at the first breakpoint - and I don't mean "the first line breakpoint", it does not matter at all where I set a breakpoint, every breakpoint after that will just be ignored. So even if I set multiple breakpoints for a few consecutive statements, it only stops for the first breakpoint. It does not matter which file either. The first breakpoint which is reached works perfectly, but after that everything goes wrong.
The functions like step over etc. also don't work at that point.
If I then just click "resume" it "goes through" but it actually changes anything, because suddenly I get an error saying some function is called on null - which I never get when I do not use a breakpoint.
If I mute all breakpoints and send my request the output is as expected. So using xDebug in itself does not seem to be the problem - but after it stopped on any first breakpoint something breaks in a weird way.
Currently my workaround is to just set a breakpoint, send the request, stop execution and add another breakpoint, send the request again ..... I can work this way, but it's really annoying and time consuming.