You can find older software on F-Droid which is not updated for several reasons. One reason can be that the compiling of newer versions of the software didn’t work on the F-Droid compile setup. And I’ve read that, if uploading of newer versions is omitted for some reason, F-Droid leaves older versions of software in their repository because there are people with older Android smart phones that cannot run newer versions, and even when there would be security issues, these users are free to take the risk and use the software.
Best to ask your question on the F-Droid forum, where you can also search for answers without creating an account and where some F-Droid devs may answer : forum.f-droid.org