umap - incorrect server response message

hi!

i create a umap-Map and get several the message "incorrect server response".

there are not many data in the area.

here the openlink: umap-example

serveral data in the area of Lübeck

my definitons for dynamic osm-data by overpass are...

https://overpass-api.de/api/interpreter?data=[out:json][timeout:25];(nw["railway"="water_tower"]({south},{west},{north},{east});nw["man_made"="water_tower"]({south},{west},{north},{east});nw["disused:railway"="water_tower"]({south},{west},{north},{east}););out center;

https://overpass-api.de/api/interpreter?data=[out:json][timeout:50];nw["abandoned:railway"="signal_box"]({south},{west},{north},{east});out center;

https://overpass-api.de/api/interpreter?data=[out:json][timeout:50];nw["railway"="signal_box"]({south},{west},{north},{east});out center;

https://overpass-api.de/api/interpreter?data=[out:json][timeout:50];nw["disused:railway"="signal_box"]({south},{west},{north},{east});out center;

Can someone tell me how I can improve performance? Not all markers are always displayed.

regards Jan (german)