Bubbles are indicative of exhaust leak.
That is a wildly odd spot to have them. Usually they would be seen around the gasket / flange.
The top pic still looks like it is wetter to the left of the stud and nut being shown.
The bottom pic looks more like coolant than oil.
How are the fluids looking?
Have you checked the torque on the exhaust nuts?
Maybe apply an exhaust sealer to the flange of the manifold. If it is a replacement (looks like one) sometimes they aren’t cast or machined off smooth allowing exhaust leaks.
Which still leads us to there’s oil in that field.
Bubbles aside, it still looks like it maybe coming from the seam from here.
However, while unlikely, it is possible that your suspicion is correct.
I think if you take a day to remove the manifold, clean the ports and seat off well, look for any obvious damage, if none found, run the engine a bit and if there is a crack like you suspect, it will present itself.
Slightly annoyed neighbors may as well, depending on where you live, if you have a garage, etc. , but at idle these aren’t as loud as at least half the vehicles that pass by my residence daily that make it a point to be louder than a train.
