[Update]: The upcoming Proving Grounds patch is looking to shake up the campaign experience, as well as finally break up the endless 'Order-tide'.
Ever since The Shadow and The Blade DLC arrived, Total War: Warhammer 2 has suffered under two rather massive bugs. The first and most noticeable one affected only the campaign and essentially made it so Vampire Coast, Vampire Counts and Lizardmen factions couldn't recruit more than a single army. Because of this, the balance of power between the various factions became even more lopsided than usual.
The second bug affected only the multiplayer mode, but it was even more insidious as it was incredibly hard to spot. This is because the bug made it so units receiving chevrons (levels) in battle while under the effects of buffs/debuffs would have their base stats set to an incorrect value. This doesn't sound like a big deal, but when multiplayer is carefully balanced around unit cost and performance, having the latter suddenly shift upwards or downwards causes quite a few problems to pop up.
Thankfully, all of this has now been fixed through the newly released King's Shilling update. The patch has also made it so Vampire Coast factions can raise dead at sea, increased the amount of mods players can apply at the same time, as well as corrected a whole bunch of bugs. Best of all, the update seems to be save-game compatible, so it's unlikely you'll have to start a brand new campaign in order to enjoy the new changes!
You can read more about the King's Shilling update, as well as follow any future announcements, over at the official website.