The wallet will stop syncing when a PoS block is found, always happened to me and requires to backup wallet.dat, delete, restart + resync, place back wallet.dat.
OMG, BROKEN COIN!!!!!!!
I was wondering what caused my wallets to stop syncing every now and then.........
It's also to me. I thought it's only my one case. It's a noraml problem. That's sad.