problem with composite map - second layer will not show

[gerdsuper]

Hi,

i have a problem with building a composite map.
I would like to add a few layers of this map:

https://map.geo.admin.ch/mobile.html?lang=de&layers=ch.bafu.wrz-wildruhezonen_portal,ch.bafu.bundesinventare-auen,ch.bafu.bundesinventare-hochmoore,ch.bafu.bundesinventare-flachmoore_regional,ch.bafu.bundesinventare-flachmoore,ch.bafu.bundesinventare-jagdbanngebiete,ch.bafu.schutzgebiete-schweizerischer_nationalpark,ch.bafu.bundesinventare-trockenwiesen_trockenweiden&layers_opacity=0.9,0.75,0.75,0.75,0.75,0.75,0.75,0.75&bgLayer=ch.swisstopo.pixelkarte-farbe&zoom=3.7016490744503514&topic=ech&E=2615664.78&N=1152355.11

to a base map, lets say Topo4U:

https://www.4umaps.com/online-outdoor-hike-bicycle-map.aspx

If i wan`t to create the composite map orux tells me that maps with different projections can´t
be combined. Basemap has MERCATORESFERICA and other layer has WGS84.

Is there a way to change one of these projections ?
I think its only a small mistake, because other composite maps work great, but i don´t get it...

Another problem is that i can only see zoom levels betweent 0-11 for the map.geo.admin layers.
But in their own homepage all zoom levels are visible.
Maybe this is due to license issues?
In this thread:
https://oruxmaps.org/forum/index.php?topic=21080.0

Orux is writing something about necessary projection, but i don`t really understand.

I did other composite maps with on- and offline maps and WMS-layer witout problems.
All of it looks very the same, but this i can`t get to work...
Maybe somebody can help me out...
THX, Henning