Try feeding one cube at a time as well as lifting and dropping. You also need to string out light shot to ensure each one registers on the float. Finally as set depth is reached the meat needs to register too on the float bristle.
Our lake has lumps in and they are very wise, they tend to intercept the bait on the drop but just hold it up, they dont bolt. Bites are just late/no registration of shot. Usually its the bigger fish too that do this.
If you are foul hooking you are probably too deep, inches matter when it comes to depth.
I now use Garbo DC6 in 0.1g with 4x 10s on strung out with the meat just about sinking the float.
You need to watch the depth as single cubes often brings them up, depending how often you ping one in. Sometime stopping feeding helps as they then look for bait and find the one with the hook in. In matches it can be a problem if the guys around are just feeding too much on your line.
There is more to shallow fishing than some people think you need to work at it.

I don’t know if this helps at all, but Ive been fishing the margins on my local lately trying to suss out different things. What I have noticed is that it is possible to fish the deeper margins with a hair rigged bait well off bottom and the fish hook themselves. i use the fox series 2 carp match hooks which are very sharp and i use a size 12 which is quite bigger than a usual size 12 and the slightest movement causes the hook to prick and they bolt, setting the hook. I use the largest preston sprinkle pole pot and trickle 6mm cubes over the top, or if i’m fishing close in i feed 1 or 3 bits of meat over the top every minute or so. I cant see why you couldn’t adapt this method fishing conventional deep shallow on the long pole, its the same principle.

In my experience fish sitting just off deck are almost impossible to catch as they seem to gill feed over the loose feed. They just seem to blow the bait around and feed off the cloud it emits but will not take any solid baits in. They do it on pellets, hemp and meat but rarely on corn. The solutions that work for me is either fish soft paste, as thay cannot resisit taking it at some point, or fish shallow as I described above. Ease off the feed, the more you put in the more you will be tearing you hair out.

wouldn’t bread work under these circumstances?

Bread is very much an underated bait in my opinion. I tend to fish it more in winter but fished on the bomb popped up is deadly. You just need to work out how high up in the water they are. The only issue is silvers will attack the bait and you can never be sure its still on.

popped up bread is the way forward on this one (if allowed)