Update
I'm done now a complete uninstallation of SH5 and deleted all files of it. Then done a reinstallation with all patches of SH5 and start it first time as stock game. After this, I install TWoS 2.2.25 and use the "The Wolves of Steel 2.2_SH5 Expansion Pack_v2.2.25_Full.exe" and started SH5 after this without any mods and done ingame settings. Everything works fine at this moment and I start it without any mods again to be sure. At this point I had a complete new and untouched TWoS 2.2.25 installation.
At the next point, I only enable "Little Ships 1.1 for TWoS 2225" and started SH5 again with sh5.exe and had exactly the same issue. Then I disabled "Little Ships 1.1 for TWoS 2225" and started SH5 with sh5.exe again and everything works fine again. To be sure, I enabled only "Little Ships 1.1 for TWoS 2225" again and got again this issue.
But I noticed, that the black screen of loading TWoS was with enabled "Little Ships 1.1 for TWoS 2225" just for a few seconds. Without and and just TWoS with no other enabled mods, the black screen be there for 3 or 4 minutes like every time.