Wrong Home Page loading

Dear all,
I need an urgent advice….
All was running perfectly but for some reason I had to recreate my English page (German was fortunately still available so I was able to copy and paste) on my Web site.

After I recreated my English page all of sudden I face a different problem…. huh!?

Let me describe my situation:
I have two domains which are configured as Multidomans by my ISP ie.
https://www.kovic.at and
https://www.marko.photo
WP is installed in https://www.kovic.at/photo

Previously I was able to get my default English page by typing any of the above URL addresses BUT now all of a sudden I can only get to my default page if I type https://www.kovic.at/photo
or
https://www.kovic.at/photo/?page_id=1320
https://www.marko.photo/?page_id=1320

https://www.marko.photo and/or https://www.kovic.at only bring “half of the page”?!

Any idea what may be wrong and how to fix this!

PLEASE!

I am desperate…

Thank you,
Marko