Transmission 2.33 fails to connect to UDP trackers

Ok... the readynas did find up to about 5 peers (I have restricted the number, see above), but within about 15 minutes it's consistently disappearing from the network. I've disabled the addon. I will try 2.23 and see if that solves it when i get the chance.

Playing with transmission on my laptop has led to new questions though. Previously my readynas with transmission was "stable" on the network when I restricted the number of peers it could connect to. I thought this was because if it connected to too many then the router was removing it from the network (other computers on the network could no longer access it, either through web browser, as network drives, or using raidator). However having seen how many my ubuntu laptop can connect to - using transmission - then this already shakey premise looks even less likely (as the router isn't treating the laptop in the same way). So..... All ideas welcome ;-) At first glance I can't see anything different between how the two transmissions are set up, although the "encrypted peers" question is phrased slightly different and so the selections are different (on readynas duo - ignore unencrypted peers; on laptop - prefer encrypted peers)