Strange that the fallback does not work although we had a positive response yesterday. We’ll have to have another look.
If you need LMS urgently, you can switch to the dev branch or wait until the next beta is released.
EDIT: Found it, the nightly build name changed
https://downloads.lms-community.org/nightly/logitechmediaserver_8.5.1~1712473975_arm.deb
https://downloads.lms-community.org/nightly/logitechmediaserver_8.5.1~1711624004_arm.deb
EDIT 2:
This should do it for now
sed -i '/fallback_url.*lms-community.org/c\local fallback_url="https://downloads.lms-community.org/nightly/logitechmediaserver_8.5.1~1712473975_$arch.deb"' /boot/dietpi/dietpi-software