User not set as post author, cannot upload images

Here’s the frustrating part — it doesn’t happen all the time, in fact it’s about 50%.

We have users that when they create an account they are assigned a custom user role.

Occasionally, not always, a user will email us saying they were unable to upload an image to their post, and then when we go into the post the Post Author is set to someone with the Author role, not the user that actually authored the post with the custom user role. The only way to remedy this is to add the Author role to their user account.

Here is our flow…

-User registers via the Ultimate Member plugin and is assigned a custom user role.
-User creates a new post via an ACF custom form, and that post is a custom post type built by CPT UI.

I’ve been over every setting in CPT, Ultimate Member, and ACF and don’t see anything missing, and further it works 50-65% of the time without issue.

Am I missing something? Is this not a CPT UI issue but an issue with Ultimate Member possible?