Man, I totally get that lol. Mine is the same way. On a sunny day it's fine, but if there's even a hint of clouds, it barely trickles any power. Last week I tried charging during a partly cloudy afternoon and it took like six hours for 20% battery. Kinda defeats the purpose if you ask me. I've seen people raving about them online, but I guess they must live in super sunny places or something.
Right there with you, my portable panel is basically a paperweight unless the sky is perfectly clear. I left mine out for a whole day with some clouds and got maybe two phone charges. The hype definitely doesn't match the reality for most of us.
That bit about super sunny places hits the nail on the head, these things are super location dependent. It makes the whole green tech push feel a little out of touch for anyone not in a desert. We just get sold a one size fits all solution that barely fits anyone.