Weird charging issue

I have an HP laptop. Envy 13-ah

When using windows (I dual boot) and if I plug in a USB C charger then the laptop charges.

If I use mint it doesn't charge from a USB C charger whilst using mint.

If I turn the laptop off and plug in a USB C charger it does charge the laptop.

Finally, if I use mint whilst it is plugged in to a monitor via a USB C cable for the display out then again it does charge.

All very weird.

Can anyone please offer any understanding of what is happening and any possible solutions to get charging working whilst using mint?

Many thanks for any help