Sometimes power adapter charges som...

There could be loose connection,
Check the same adapter with the known good unit>If that works fine with the diff unit , which means the charging port must be lose.
If that acts in a same way on diff unit as well,
you can try replacing the adapter

the connector in the computer is connected to the mother board and it tends to crack (design flaw) thus the connection becomes erratic solutions are 1)replace mother board 2) if you know someone really good at pc laptops and slodering u open laptop dismantle and sloder connections 3) replace laptop 4) unfortunately live with jiggling until it charges