I agree 1W is not enough to keep the electron charged, I would recommend 10W unless you are sleeping a lot… then 2-3W might be enough to get you by. I guess it really depends on how much sun you have (sounds like tons) and how often you are waking and staying awake for.
The battery protection IC in the battery should not limit the default current rate at all. It should allow charging rates of up to 1C easily, and we only charge at 0.25C (512mA) by default.
If you see the first post, with data… we have tried but don’t have an exact repeatable test that we can perform over and over. There are many ways to mitigate this issue though as you are testing now.
Please do submit a minimal repeatable test case and collect the bounty