While mining (on testnet) my node appears to get peer-banned and then forks off. Veil from a previous testnet session (a week earlier) appear in the transaction list, even though the previous data folder was deleted, but the original wallet was restored from the Seed words, not from a wallet file.

I connected to a testnet peer addnode 145.239.0.50 add which then connected me to a total of four peers. (That peer node belongs to veil.suprnova.cc)

The blocks began loading from the genesis block, because I had deleted the previous data folder entirely, that had (a week earlier) generated many blocks without any connected peers.

After becoming fully synchronised I started mining generatecontinuous true 4. This is on a MacPro with a 6-core 3.5GHz Intel Xeon E5 cpu and 32 GB of RAM.

My wallet immediately began generating a surprising percentage of the blocks. Difficulty increased from about 3 to over 7. Later I realised that one of the four peers was no longer connected, and had fallen 1,000 blocks behind. I had over 11,000 Veil and I checked the transaction list and saw the Veil that had been generated previously by this wallet address, but the associated data folder, including the wallet file had been moved. This data folder was completely fresh!

I then realised that the other three peers had disconnected. Occasionally a peer would appear for a fraction of a second and then disappear. I checked the blockchaininfo and saw that the difficulty had reduced to about 0.0003 (from over 7). While connected, Zerocoin generation was also active, and I have to wonder whether appearing in the network and having (one or many) Zerocoin mintings rejected, might add to banscore and then get you disconnected from all of the peers, and then forking off, while generating blocks that will not be seen by other peers.

The only other hypothesis I have for how these basecoins and zerocoins could have been recovered (by seed words) is that maybe I had a connection when it appeared I did not??