I too am experiencing OsmAnd+ freezing regularly & seeing the "OsmAnd+ is not responding" pop up, often when trying to place a map marker. App often takes up to 30 seconds to place a map marker.
I have not subscribed to live updates. Active plug ins are online maps & contour lines. I had some additional side loaded maps - British Isles Addessses Nationwide & England/Scotland/Wales Postcodes Addesses Europe. I have removed them but the problem persists. I have uninstalled/reinstalled the app & deleted all maps then re-downloaded them to see if this helps.
Note 4 on 5.1.1 unrooted. OsmAnd+ 2.3.3
PS another strange behaviour since update to 2.3.3 is that I don't use night mode yet when searching for an address then selecting from the results there is a lengthy pause whilst the app seems to display in night mode (the background is dark & only partially drawn) before it eventually displays the map with the marker in day mode