- Edited
Just to make sure we are on the same page. My files are on an external memory stick which I connected to the phone via USB-OTG. I did not wipe the internal storage via TWRP before installing the ROM. That is what I read in multiple tutorials. Is that correct?
I watched a video in which both zip files, for ROM and GApps, were selected and installed together. I could try that.
EDIT: I saw your EDIT now. Thanks. I could not take photos to illustrate the issues. Funnily, whenever I pressed screenshot the anomalies disappeared. But believe me, everything is weird. For instance, upon shutting down, there were 4 "shutting down" windows, a big, central one, and three in a row at the top of the screen. Some for Wifi and anything else.
I have begun another install. This time I have got "Unable to mount storage" in red after each wiped partition wiped, but the wipe was considered successful. I could not delete files from the internal storage manually nor I could wipe it.
I re-installed loading both zip files, ROM and GApps, simultaneously. I am still facing the same troubles though