I got the Antroch Stone + Antroch perk roughly about the same time.

Now I notice that I have to cast a conjur companion spell 2-3 times before it will actually work.

The spell builds, I point down, I get the normal "sound" just no blue circle thing that anything pops out of.

Anyone else have this problem?

It's a well-documented bug. Conjuration spells are apparently considered self-targeting offensive spells, so they have a chance equal to your Magicka Absorption to be "absorbed" for no effect. Thus, the Atronach perk combined with the Atronach standing stone mean your Conjuration spells have an 80% chance of failing, which can be a real problem if you need to recast one in combat to stop a charging enemy.

Restoration heals are self-targeting as well, but they're not flagged as offensive spells, so they're never absorbed.

If you're on PC, check skyrimnexus for a mod solution. If you're on a console, just pray Bethesda fixes it.

Thanks for the replay.

Kinda kills my mage hunter's hopes and dreams though.