One last note on this, as it just occurred to me. It probably wasn’t the Linux kernel version, but I recently set the battery charge limit in the BIOS to 80%. That’s about the time this started happening thinking back.
I did this, because for the most part this laptop is at home, and rarely do I need it to last longer than a few hours. I figure it would be better for battery health to not fully charge it.
So, seems like it may be a bug with BIOS battery limiting.