Help: systemd service keeps failing on Debian 12

Actually I did not do nothing special, just installed fresh VM from template and my custom service wont start
Here is log:
Feb 13 10:42:23 vps systemd[1]: myapp.service: Failed to load configuration: Invalid argument
Feb 13 10:42:23 vps systemd[1]: myapp.service: Unable to locate unit myapp.service

I checked /etc/systemd/system/ and file is there but systemd says no
Not my circus, not my monkeys but maybe someone seen this before XD
Provider is Contabo if that matters

The error "Failed to load configuration: Invalid argument" typically indicates a malformed unit file rather than a missing file. The "Unable to locate unit" message often follows when systemd cannot parse what it found.

Please check the following:

• Run `systemd-analyze verify /etc/systemd/system/myapp.service`
• Check for a Byte Order Mark (BOM) at the start of the file: `file /etc/systemd/system/myapp.service`
• Verify line endings with `cat -A` — you may find CRLF sequences (^M$) from a Windows transfer

The [Install] section requires WantedBy= or RequiredBy=. A common template error is omitting the target or using an invalid dependency name.

Also check if Contabo's template mounts /etc/systemd/system as a symlink to an overlay that does not propagate writes correctly. I have observed this behavior with providers using read-only base images and writable overlays on older kernels.

Simple is better. Check
Check if the template shipped a broken unit in /lib/systemd/system that shadows yours