Upfront Builder homepage not showing correctly even after layout reset

Hello,
for my homepage I am just using Upfront Builder (no Upfront Editor) because that's the only way I can then export my theme (via zip file) to another site if I need, without making all the customization (via Upfront Editor) again.

I granted you access and had a chat live session with @Rupok but he was not able to find the issue.

The problem is the following:
* changes made in Builder (e.g. adding new region, modifying text, etc.) do not appear in the live site.
Please note that I did NOT modify anything in Upfront Editor (so my site should be exactly like the theme in Builder!).

I even tried the following:
1. made some changes in Upfront editor -> these are reflected correctly in the website
2. go to Upfront -> General -> Resets layout to default look, be careful and click on RESET HOMEPAGE LAYOUT
3. still, the website does not reflect the theme in Builder but the (now old!) changes made in editor!!!

Looking forward to your reply, thanks.