If the now missing results are originating from SSL/TLS services this should be also the same as dicussed in "Report Vulnerable Cipher Suites for HTTPS" VT not reporting in GSEv22.4 and which seems to be fixed with Fix: determine SSL/TLS support on services by jjnicola · Pull Request #1176 · greenbone/openvas-scanner · GitHub.
One additional important note to the following
The “Ports” tab in GSA doesn’t list every open port found by a port scanner. Instead it lists (by design) only the ports on which at least one result from the current used filter has been found.