Facebook ads learning phase completed in 2 days

Hey,

I have noticed recently that FB ads have completed their learning phase in 2 days and give the
"This ad set generated fewer than the recommended number of purchases"
I got 38 conversions in 2 days.

I thought that you need to get at least 50 conversions within a week for the learning process to complete, but for some reason it completes itself so early now.

Any idea what might cause that?

I think you are mixing things up. Yes you need at least 50 conversion in order get information in your reporting, but learning phase is something different, every time you change something on the ad set Level the learning phase starts again.
Basically the learning phase is the algorithm that tries to hit all the required target setting.

Yes I know that.
But if you don't change anything, the learning phase should take roughly 50 conversions to even out and end the initial phase.
What I am saying is, without changing anything, the learning phase ends within 2 days instead and says I didn't get enough conversions in those 2 days.

What happened to me is that I got a decent ROI the first 2 days, then 3rd day learning phase finished and campaign completely tanked (I didn't change anything).

Ok hard to tell what happened with the information you’ve provided so far. It sounds weird indeed.
What exactly you mean with a decent ROI
Maybe you can post a screenshot.

First 2 days I had a 50% ROI with 38 conversions in total ($200 daily ad spend)
3rd day initial learning phase completed and I got 0 conversions. Did get the add to carts though.
This has happened before as well. When I restart or duplicate the ad to a new one, will get sales again for the first few days and 3rd or 4th day always tanks completely.