Every update mobs get 'revamped'. Meaning they get stronger. However, the current state of the game does not allow you to progress to handle these adjustments. If the mobs stay as is every update and you add new zones to the game with 'revamped' mobs, people can stay at their happy place and proceed to advance and check out the new zones when they're stronger.
Currently the only thing you can do as a solution is tone down the mobs back to what they were. Example is Cemetery, I used to farm there solo, now you re-vamped it and I get blown up in a couple of hits.
Just hold your horses on making stuff stronger, you can do that in new zones, the lineage 2 lands are big enough.
For now, tone down the mobs you've boosted.