Kobo Clara showing 55% battery when charging

Hi,
I am new to this forum.
:help:
I noticed recently that when I plug my kobo Clara (colour) to charge, it shows 55% and will show that for hours … it’s only after I remove it from charge, does it show 100% or wherever I stopped it.
How can I remedy this? And is this a problem others have had?
It just started last week. Was not happening before.

Thanks for all your help.