Why does btcd keep stalling while syncing the chain?

[molxyz]

Yesterday I noticed btcd stalled for two and half hours, I had to manually restart it. Now looking at the log screen I saw the timeline had a gap that showed btcd stalled for about 4 hours before progressed again. Here's my log:

2018-05-07 00:56:52.947 [INF] SYNC: Lost peer 107.189.42.203:8333 (outbound)
2018-05-07 00:56:53.615 [INF] SYNC: New valid peer 119.28.187.169:8333 (outbound) (/Satoshi:0.16.0/)
2018-05-07 05:03:12.740 [ERR] PEER: Can't read message from 209.159.151.144:8333 (outbound): read tcp 195.181.243.196:55570->209.159.151.144:8333: read: connection reset by peer
2018-05-07 05:03:12.740 [INF] SYNC: Lost peer 209.159.151.144:8333 (outbound)
2018-05-07 05:03:23.252 [INF] SYNC: New valid peer [2001:0:4137:9e76:4d7:37bd:bbc4:bf8]:8333 (outbound) (/Satoshi:0.15.1/)```

EDIT:  It's hanging again right now...  

2018-05-07 07:27:09.808 [INF] SYNC: Syncing to block height 521602 from peer [2a00:1a48:7810:101:be76:4eff:fe08:c774]:8333
2018-05-07 07:27:09.808 [INF] SYNC: Downloading headers for blocks 355822 to 382320 from peer [2a00:1a48:7810:101:be76:4eff:fe08:c774]:8333
2018-05-07 07:27:13.815 [INF] SYNC: Verified downloaded block header against checkpoint at height 382320/hash 00000000000000000a8dc6ed5b133d0eb2fd6af56203e4159789b092defd8ab2
2018-05-07 07:27:13.816 [INF] SYNC: Received 26499 block headers: Fetching blocks
2018-05-07 07:27:39.886 [INF] SYNC: New valid peer [2001:718:ff01:2:0:93ff:fefb:fdf8]:8333 (outbound) (/Satoshi:0.12.1(bitcore)/)