I don't know, if blockchain restarted, but I don't see a lot of orphaned/lost blocks.
I've seen normal number of orphaned blocks as usual.
System is coping with a lot of switch off/on miners, and it's boggling a little as we see.
But still it's much more stable than it was year or 2 ago.
@gjhiggins, will probably tell us the cause of this, but I think nothing big happened, really.
I've seen also, that POS blocks were almost absent in blockchain recently.