Recently used plugins won't work for replacing a synth

Hi! I've noticed that when I'm going to replace a synth that won't work if I choose Recently Used Plugins (Sonar update 2017.07).
If I choose one of them Sonar will just insert a new VST on Synth Rack, but won't replace the synth.
 
Also I noticed that if I insert a VST only on the synth rack (and not as an instrument track), then I can't choose it as a midi output to a midi track or an instrument track, because it won't play sounds.
I remember I would just change the midi output on track inspector, and it started working, but now I have to split the track instrument and change the midi output on both midi and synth tracks (and then make an instrument track back again).
 
Has someone seen these 2 issues?
 
Thanks!