After some back and forth with Strymon, this is their response
"It looks like this particular issue has come up specifically with the Singular Sound Aeros. The reason is that our power supplies ramp up power instead of sending the full amount all out once. There are a few pedals that don’t react well with that, hence the reason it sometimes works and sometimes doesn’t.
Some people have more success if they have the Ojai turned on already, and then plug the power cable into the pedal.
If you were to send this in for repair, it most likely wouldn’t have any issues that need repair and would be considered functioning correctly.
You are more than welcome to reach out to the Australian distributor Noise Toys Imports if you’d like"
So I wouldn’t recommend using Strymon PSUs, given they either will or won’t work, but neither reliably.
Apparently the fact that I have one Ojai that’s reliable and one that isn’t doesn’t count as a fault!