Hi, not sure what the problem is, but you can try executing the command with exec myScript.sh to test. Follow it with echo $? to get the exit status. Exec will close your terminal session so maybe wrap it $(exec myScript.sh)
The Shebang(#!) must be on the first line of the file with no whitespace between the start of the file and the Shebang.
Try a space between the Shebang and the /bin/bash. Most of the time it doesn’t matter because it’s launched from a shell and processed by that shell also exec is usually smart enough. In this case it may be that the exec command processor is looking for the area between the first space and the end of the line. I’ve seen this happen on a Linux system before. Not HA, but others.
BTW. HA default is #!/usr/bin/with-contenv bashio. Try this one.
Here’s a list of valid Shebangs I found on the terminal addon. Run On Startup.d