It turns out that the latest update for Apex Legends (the 1.1 update) caused player records to be moved to the wrong servers, causing some players to lose their progression.
Namely, the server that the records were moved to had no record of player "persistence," said u/Jayfresh_Respawn on the Apex Legends official Reddit. He said the following:
“When the 1.1 update went live, players were unintentionally moved to the wrong servers that didn't have their persistence and this caused players accounts to appear reset with all progression lost.”
“Fortunately, your progress up until the update was still safe and sound. We shut down all live servers so we could remove players from the wrong place and roll up the correct servers with your progress. Once we confirmed internally that we had fixed the issue we started rolling out the right servers starting with Xbox and staggered the updates to PS4 and PC.”
“Everything you've accomplished and bought in Apex up until the 1.1 Patch that went live at 10:00 PST today should be restored.”
“- Any in-game purchases and progress acquired during the time between 1.1 going live and the fix will be reverted - levels earned, items unlocked, packs opened, and spent currency. If you continued to play and didn't patch then this will not affect you.”
“- Any currency purchased, spent or not, will be carried back over to their original account state. i.e. - if you bought $20 worth of coins, and spent $18, then you’ll will get $20 after the fix.”
This is why it looked as though progression had been lost along with all purchased and crafted items. Fortunately, Respawn sorted out the issue relatively easily. They moved all the data back to the correct servers and everything was reverted back to normal.
The developer advised players not to buy or craft any items until the issue has been resolved. But now you can again spend your hard earned Legend Tokens and Crafting Metals, as usual.