My Samsung Galaxy A5 (2017) (a5y17lte) came with the latest StockROM 8.0.0 Oero firmware version including the latest bootloader & modem firmware and with security patch date is 2019-11-01.
After overcoming the Samsung obstacle of the encrypted partition /data I was able to install @Unknown Build. The following pictures show the status:
But - after switching off the A5 2017 completely by using the power button the phone restarts by itself after a few seconds. It is a boot loop without end.
I have tried several tips from this forum and external forums to make this error harmless. Unfortunately without success.
Next, I installed an unofficial build of Resurrection Remix OREO 8.1 for Galaxy A5 2017. After switching off: It is a boot loop without end - identical to the first mentioned unofficial e-0.7-o-build-Unkown.
The last test installation for the time being is the 9-pie LOS 16.0 image of LineageOS-for-microG Build from 16.12.2019.
Here the above mentioned error of automatic power on does not occur.
I agree with the opinion of @Manoj’s “Time to get rid of nougat builds and officially upgrade to the next level…” which in practice means leaving 8-Oero behind and going all the way to 9-Pie.
Also @GaelDuval said some time ago “We have added support for Android Pie in 2019, and will add support for Android Q in 2020.”
Yes, he’s absolutely right!