This was actually mined, the transactions in the blocks until 2010 appear valid, all of a sudden after that period all transactions disappear from the history, it was not purchased or something like that
I hope you made a copy of your wallet.dat for backup purposes.
You can try to rescan it if you think that it's not properly scanned the first time.
If your Bitcoin Core isn't set to prune old blocks, you can enter the command
rescanblockchain to the console to re-initialize scan.
To open the console, go to: "
Window->Console" | Make sure that the correct wallet is selected in the console before entering that command.
If Bitcoin Core has pruned the old blocks (
see the if this is ticked: "Settings->Options...->Prune block storage to"):
I'm afraid you'll have to restart from scratch since the 2009~2010 blocks are the first to be pruned.
You might consider disable pruning first (
if it's enabled) if you have the disk space.