I appreciate you bringing this to our attention, jluros.
Yes, you're correct. The link is only visible when customers are paying their invoices online and should not be showing up on their statements.
To get this sorted out, I'd suggest getting in touch with our QuickBooks Payments Support to have this investigated.
Unlike in this public forum, they have the tools required to perform any escalations in the system whenever necessary on your behalf. You'll first have to review our support hours to ensure they can assist you on time.
Additionally, you can visit the following links below. These will provide you more details about customer statements. Also, you can find product updates for QuickBooks 2020 for Mac (Version V19.0.4 R51):
Release notes for QuickBooks Desktop for Mac 2020.
Create a billing statement.
I hope that helps you get back on track! If there's anything else you need, please let me know. I'll be around to keep helping.