Max IPTV sources in Free version on ProgDVB

I have the latest free download of ProgDVB Standard 7.28 version installed on my Windows 10 laptop. Under Settings/TV Sources(Advanced) it appears that I can only have 2 IPTV sources. If I try to add another IPTV source, using the +IPTV Client button, it simply changes one of the ones already set up.. Is 2 IPTV sources the limit on the free version?