I have gotten so much from this forum so heres something I want to add.
If you notice less bubbles emanating from your ozonator it can be telltale. In fact its likely not your ozonator nor its injector. I learned hear that most of the bubbles are just air that is being drawn in along with a bit of ozone from the oz generator.
In my experience diminished bubbles are due to circulation problem. usually something as simple as a water intake blocked with yuck of some kind or a clogged filter that needs at least a good rinse and perhaps a chemical clean. Both those conditions can cause other problems including hi limit switch/ breaker tripping.

It's amazing how this issue and many similar problems can be related to old or clogged filters. The first thing to do before assuming you have a problem is to install new filters. Then, continue trouble-shooting. You'll be surprised how many problems you can solve simply by installing new filters!

So a good check would be just remove the filters for a bit (assuming no serious debeis in water) and take a peek at the bubbles. You may also actually here your pump struggling less. PS see my post on paper vs tri-x style ( ceramic? )filters. Basically my opinion is save a buck go with good paper.