My guess the package/repo Signature / Digest is no longer acceptable for modern OSes.
The software creating the RPM package probably needs to be updated to reflect current minimum security requirements.
I am using RHEL 8 and the work around i used was to disable FIPS mode and reboot.
You can also try:
rpm -ivh --nodigest --nofiledigest <dir_path/openhab2_pkg_file>
References: