I had some problems in my project and found that the substring-after block is doing some strange stuff.
I already tested it in some seperate project and reloaded the libery.
The block gives me the inverted substring before the char i use and sometimes it uses one more char wich comes after.
The code of "substring after" block uses blank for the custom block above, which won't work properly because of using the former code. Fixing using the latter block fixes the issue. Meanwhile, you can do this.
for some reason, i checked the definition of the "substring frop pos. to pos. inclusive" and the "substring after str" reporters and nothing seems to be different but the block works correctly now so idk