Hello,
I'm sorry to hear that you faced a problem during your game.
Usually, beacons will appear randomly so sometimes it will take a long time. But if you sure you found 0 beacons for a long time and since everyone else also having the same issue, it probably a bug.
You can make a bug report
here with evidence if can such as video preferably to support your report.
For your condition, if you want you can use disenchant to remove Treasure Hunter and Treasure Seeker enchantments from your pickaxe and see if you can find beacons like normally. Hope this helps.
Now this one is confusing me. I also thought it only works for event, but some people say its not. I forgot the full description of it, but I've tried myself during The End of Season Event and on the max level, beacons appear far much often than normally which means it should work on normal mines too.