I appreciate you joining this thread and providing feedback, @VanguardAudioLabs.

The open investigation about being unable to select different Custom Form Styles when making invoices is now closed and resolved. Since you're still experiencing the issue, I recommend reaching out to our phone agents.

They can run the screen sharing tool to conduct further investigation on your company file. Open the link below to get their contact details.

Contact the QuickBooks Online Customer Support team

Keep me posted on how the call went, @VanguardAudioLabs. I'm just a post away if there's anything else you need. Take care always.