We looked at your report but did not have much fresh ideas.
checkNextState errors are probably because app calls api methods at wrong time (starting connection from ui while client is connecting e.g.).
Aside that, everything looks like poor internet connection which causes disconnects.
Can you try to run particle demo from Photon javascript sdk package to see if it fails as well? It has average data send rate. If your app sends more, it can work for high bandwidth and do not for lower.
Btw, you did not fully answered my previous post on this topic