“Misbehaviouring” and “crazy” are unfortunately not particularly descriptive.
Those terms are unfortunately closer to “it broke” than to something that we might address.
Which particular LG monitor are you using?
There’s also that at least some LG display monitor devices will have their own teardrop-shaped cursors, and those can sometimes also have issues unrelated to Ventura. I’ll assume you are not referring to a WebOS cursor.
Again, please describe what is happening with the pointer, as if you wanted to describe this behavior to somebody that cannot see what the pointer is doing, doing differently, or not doing.