On https://www.erlang.org/downloads (note the plural s) OTP versions 17+ are listed. At the bottom of the list of versions, the following notice is displayed:
Older releases and a file containing MD5 checksums for all files in the download directory, also reachable through
rsync rsync.erlang.org::erlang-download
The text “download directory” is a link to https://erlang.org/download (note the missing s) which appears to be a broken link. It appears rsync.erlang.org is down entirely:
$ nc -vzG5 rsync.erlang.org 22
nc: connectx to rsync.erlang.org port 22 (tcp) failed: Operation timed out