Email Forwarding from some addresses never reach destination

I have setup an email forwarding rule for my domain to send messages to a gmail account. It works… sometimes. Some addresses that messages are sent from are never delivered, others reach it. If I send an e-mail directly to the gmail account from my cox email, it gets delivered. If I send it to the Cloudflare alias from my cox email it never appears, but I do see it in the Cloudflare console as forwarded. If I send from my work email to the Cloudflare alias it gets delivered.

Early I was trying to migrate my financial planning account to this new email alias and my advisor sent an email to my cox email and my Cloudflare aliased email address and it arrived to my cox email but not to my gmail account behind the Cloudflare alias. Again, I can see it in the console listed as forwarded.

Any ideas where this issue might be living?

Thanks

I can’t figure out a way to edit this, but just to confirm, I’ve checked the gmail spam and don’t see that it is reaching any part of gmail presentation layer.