I’ve been digging in to this and found out that both the webpage and the registration are asking for the correct page.
For som reason the page does not get generated! as a consequence of that it tries to generate it again and again, showing the header multiple times.
So in core it is not a shortcode problem
Found it!
You still have an issue with elementor but I got it working again.
When using SeatReg users MUST use the theme page layout as default!
When using Elementor full size you are toast!
This has to be don in the website settings Lay-out.
Pages that still need elementor full size can set this in the page settings (wheel in center top of page) ->settings -> at the bottom: page lay-out.
I hope this helps others with Elementor inoperability, helps you to look deeper in to it.
Can I still make a suggestion? Is there a way to go to a landing page by choice after payment selection (Booking registration)?
Glad to hear that you found a workaround. Is it possible for you reproduce the issue at https://tastewp.com/ using Elementor free version? Would help me a lot.
Did you meant the booking selection on booking status page? So when clicking custom payment button it should redirect automatically to custom webpage? Or better option is to allow to add links in custom payment description.
I’ve tried to reproduce it. Sadly enough I was unable. (Still if I switch back I have the same issue)
When clicking on a PayPal or strype payment and the payment is made it would be nice to be able to redirect automatically to custom thank you webpage (Perhaps it could include the status of the booking with another shortcode?) Also it would be fine when the custom reservation is made they end up on a personalized thank you page.
This way it can be personalized depending the chosen method. (for instance staff member with a free reservation wouldn’t need to use a money transfer info page.)
I will add those ideas to the list. I will also mark this thread as resolved.