I'm Stumped! Battery is Not Charging. Power Source: Power Adapter

Hey, so I spilled tea on my 2015 macbook air(13”) and had connected it to the charger after drying the liquid but obviously that was a bad idea.

I contacted apple and they told me the location of an authorized service provider near me and I took it to them for a diagnosis and repair.

They replaced the left I/O board or simply reassembled it I’m not sure and also changed the I/O flex cable.

Now before sending in my macbook I was using a third party charger and it worked just fine however I did notice one day the condition of the battery in the menu bar said ‘replace soon’ but it never interrupted my charging whatsoever.

After this repair from the authorized service provider, I noticed my charger would only charge up to a point and then it would only power my laptop and the menu bar would show ‘battery not charging’. I tried another third party charger and it charged up until 20% (from 5%) and wouldn’t charge after that.

I took it to the service provider again and they used an original magsafe charger and it charged my laptop up until 41% and it stopped charging too and was only providing power to my macbook.

What do you think the issue is here? Because many threads I’ve read said that fixing the I/O board should have helped. The service providers said it might need new batteries but my question is how was it working fine before I sent it to them.

What I think is that they didn’t do the I/O fixing properly and this issue is simply the outcome of the tea spill which hasn’t been dealt with carefully since if the I/O board and cable have been fixed the issue shouldn’t be present.