Need help for a Golemancer with mana problems

Hi guys.
I'm playing a golemancer level 99 and I'm having a mana problem. Despite what I think is a sufficient mana pool, I keep running out of mana and mana regen doesn't seem to work: I have to use the flask and sometimes I'm not fast enough to avoid being killed.

This is my pob: https://pastebin.com/szGgE788

I'm playing with 7 stone golems, 1 chaos, 1 lightning. The build is a mix of damage and survivability, I want to get level 100, but without having to wait 5 minutes to kill a boss.
I'm using Mind Over Matter, but I don't think that is the main cause of my mana problem, because mana should regen by itself when goes to 0.
This happens with all kind of map mods. I avoid life, mana and es reduced regen mods.
I've tried to swap my rings for a couple with mana, life, and 60% mana regen (each), but the problem stays.
I got CWD + Molten Shell + Flame Dash linked to inspiration and I got Desecrate + Flesh Offering linked to Lifetap. Using Clarity doesn't change things.

The golems don't seem to consume my mana, there is something preventing the regen.

I'm not a rookie, but I'm not expert either. What am I doing wrong?

take "sovereignty" on the skill tree.

Thanks for the answer.
After a month of trial and error, here's my conclusion.

I've tried taking the suggested node, but doesn't change things.
I tried also without mind over matter and it's the same. The mana suddenly drops to zero and doesn't start regen, forcing me to use the flask.
Stone golems cost 58 mana at level 24, chaos and lightning cost 60. I thought that maybe was them consuming all the mana at once, but how? When they fight the monsters the mana stays at max, and this proves that can substain their skills, and suddenly goes to zero.

I tried also changing the skill tree and taking the nodes that reduces the mana cost of skills: Dreamer, Tireless, Righteous Decree and the small nodes around them. But nothing.

I still don't have a solution.
So I decided to change completely and transform the life build based on the Brass Dome armour, in an energy shield build.
I'm using Shavronne and all different gear with corruptions that give my golems higher level. Now stone golems are level 28.
Minions have now more mana cost, but I don't have the mana drop anymore. Still using Mind Over Matter and nothing that reduces the mana cost of skills.

So far is going strong. Minions deal way more damage and seems pretty safe from one shot kills. I'm also immune to extra crit damage thanks to a couple of nodes and the Watcher's eye jewel determination mod. Immune to curses, shock and freeze, thanks to jewel corruptions and flasks.

Here's the POB for the ones interested:
https://pastebin.com/4h51CJpK