Invega probably blocks it. Most (maybe all) atypical antipsychotics block the 5ht2a receptor (among others) which is what shrooms hit.
The classic antipsychotics are not serotonin antagonists (at least the ones I know of. I was on moban and it didn't block trips.)
"Typical" antipsychotics are primarily dopamine antagonists, yes. I believe the butyrophenones (haloperidol) tend to be fairly selective for dopamine, whereas the phenothiazines (ex.: chlorpromazine) may also have decent 5HT2A antagonism.
It is this dopamine antagonism that seems to result in a spike in prolactin levels, although this is generally considered a relatively minor issue compared to their other side effects.
Second-generation or "atypical" antipsychotics are primarily 5HT2A blockers, and as such will seriously dampen any kind of trip. Out of these, risperidone/paliperidone (risperdal/Invega) can be considered the most "conservative", as it also has decent affinity for dopamine receptors, making it a highly effective medication in stopping and preventing psychotic behavior. Olanzapine is similarly effective while barely affecting dopamine receptors, although this is due to its blocking effect on other serotonin and adrenaline receptors, which can result in side-effects including significant weight gain and low pressure. As such, at least at low doses, risperidone/paliperidone is probably the more well-tolerated solution.
If Invega works for OP, they should probably think long and hard before stopping it altogether. They could try reducing the dose if they're feeling up for it, though.
In some cases of antipsychotic-induced hyperprolactinemia, patients have had success with switching to or adding on aripiprazole, which is sometimes referred to as a "third-generation" antipsychotic due to its action as a partial agonist at the D2 dopamine receptor, which can moderate the activity of these dopamine receptors to a level where there is a much lower risk of hyperprolactinemia.