Mid 2015 Macbook Pro - Charging issues?

Hello,

I have a Mid-2015 MacBook Pro that I've had for a few years. Over the past 2-3 days, I've noticed that in the menu bar, I've been frequently getting the "Battery Not Charging" icon that displays a plug. I've reset the SMC controller a few times. This seems to happen after the computer falls asleep and wakes back up. I replaced the battery in February 2020 with a brand new one. Everything worked fine up until 2-3 days ago. I've ran the Apple Diagnostics tool, everything checks out. Also, I've "cleaned" the magnetic charging connections on both the cable and the port. Also, have tried another replacement port (made no difference) and a different wall outlet. The system report says that everything is good; cycle count is only 18 or so. I'm running MacOS Big Sur and am current on all updates. The Apple Diagnostics reported no errors. Also, I've reset the SMC already. Not sure what this could be? I'm out of ideas at this point...