andorid headunit

Recently got this headunit but since putting it in for some reason it don't save the memory, it'll save for a couple of hours but after that all the radio stations and presets go back to default, weird thing tho is the time is fine, playing music from usb is fine plays where it left off, but...

After recently buying a used xtrons 7.1 headunit, i wasn't 100% happy with the performance as sometimes it would lag and apps would crash the system, requiring a hard rest. this still presisted after using recovery tool to flash the stock rom, so after a couple of days researching room i choose...

For the past couple of days i've been debating on which xtrons units to get. First one is a xtrons pa77aa3p and the other is a PA78AA3IP The price difference between the two is £29.99, but i can get the pa77aa3p in a matter of days compared to the andorid 8 one that comes from hong kong...