hmm. i thought i had tried/checked the AGL image.. but i don't have it running now anymore. i will need to check that again. Unfortunately, i am going away for the next few days.. so I won't be able to look into that and help until next week..
and it's been a while since i've used qt5.. a long time ago i had a working Qt5+EGLFS+GLES on freedreno/mesa using this branch:
It's a very old meta-qcom layer, so don't use it, but you can check the top most commits. I am fairly sure it used to work, and we had a qtbase bbappend there. I am not sure if it's still needed , since i haven't followed meta-qt5 since at least 1 year..
if the problem is still there next week, i can try to setup the environment to reproduce the problem and help more.. let me know if you get anything in between