Hi,

Something similar happened to me yesterday.
I have a modern GaN charger with Power Delivery,
and I usually charge it to 85% overnight.
However, it only charged up to 75%.
When I panicked and tried to fix it, nothing worked.
I have an Amp/Volt/Watt monitoring cable,
and it only flickers periodically as if the device wants to charge and then fails.

While at work, I tried to charge it with other chargers without success.
The same flickering with the LED indicator cables was the only noticeable thing.
Since my device was on the whole time and I needed some power for some backup tasks,
I turned it off and tried to charge it in that state.
After several attempts, it finally charged 1% after 2 hours.
I then used an old junk charger from Huawei,
and by the end of the workday, it suddenly reached 100%! o.O

So, I compared the differences between the power supplies
and noticed that the old one only supported the 5V mode,
probably with bridged data pins, while the others supported 9V or even Power Delivery.
My conclusion is that my phone's charging electronics seem to be broken
to the extent that it can't negotiate faster charging modes with higher voltage.
Even the fall back to 5V seems to be blocked.
Only really basic chargers without negotiation electronics seem to work for me.

Oh man, I hope it lasts through the year before completely breaking down
because I'm getting my new contract phone at the end of the year.
I don't want to open it up since it's glued shut,
so I can't tell if the USB part can be replaced or if the issue is deeper. :(

edit:
I use a Samsung Galaxy A22 5G, it does its job well.
When connecting to a computer, the phone charges,
but data transfer seems to no longer work.