Mail forwarding questions

Hi all,

I recently set up mail forwarding to forward every email to another non-proton inbox.

48 hours into this, I have noticed emails missing from the other inbox. It appears they did not get forwarded. I cannot notice anything about these emails that would have prevented them from being forwarded. Does anyone know why this might be?

Additionally, I realized that I don’t know how to see in Proton which emails were forwarded. I guess I was expecting them to be shown in the Sent folder, but they are not. Is there a way to see this?

I submitted a report to Proton themselves, but was curious if the community had any insight. Thanks.