You can see the jamming happening right now in most recent drone footage. I don't think Russia was ready for the drone menace early on. But jammers/jamming is pretty common now in Ukraine. If you see any drone footage where a drone is diving in on a target and they go static as they approach that's the jamming happening.
For now, they have limitations. The race is on for countermeasures for jamming and also jam proof signals.
Are you sure that isn't just line of sight loss? If that is jamming they are waiting a little late. Usually on those they show a view from a second drone recording the approach and impact.
I remember at the beginning they had some raygun things, but you had to see the drone coming and aim at it. Not sure how that would work if you were being swarmed with 50.
And jamming will only be effective until they get autonomous AI drones, which might not be as far off as you would think.
This is all so weird to watch on youtube. It's the live proving grounds for the next conflict coming soon with russia and china. Feel like watching WWII weapons and tactics being proved out in the Spanish Civil War right before the big one.