Power button only works sporadically when on battery

I have a JBL Xtreme 2 music speaker where the on/off button only works sporadically for turning it on.

When it finally is turned on the button always (as in 100% if the time) works when turning it off.

If the speaker is plugged into an outlet using the charger the button instantly turns on the speaker.

So to recap: When wanting to turn the speaker on when it runs on battery, the button only works sporadically - as in I have to pres the button 3 to 10 times before it turns on. The button works 100% of the time for turning it off or for turning it on, when it is plugged in via the charger.

Once the speaker is turned on the battery can keep it playing for hours and hours... So I do not see this as a battery issue.

The speaker has always been used in our bathroom sitting on top of a closet furthest away from the shower, so it has been exposed to some moisture.

Any suggestions as to what the cause could be?

ChatGPT suggested a slightly corroded connection on the power on button - but would love to hear from people here as well.