If the hole has not been cleaned there will be enough friction from dust to require a hammer to fit the anchors.
OP best bet is to pull the bolts and inspect the threads, if they look good, then try to save these anchors. Use something like an old spoke or a skewer to break up the dust in the bottom of the hole, it will be compacted now. Blow or suck out the dust, measure hole depth and compare to the bolt length, you should also be able to feel how deep the cone is set too. If you need to cut down the bolt, do a nice cut and put a chamfer on the end, make sure the thread is clean and free from burrs.
If all this fails, then don’t go and drill new anchors next to these ones, when you fits the second set, the force might crack through and it will not be secure.
If you have mangled the bolts and they cant be removed then the last option would be to fill the gap under the ground anchor. Clean out any dust then pumping in some resin for fixing studs in masonry. It will set rock hard and bond to metal and masonry.
Like these, check but should fit into a normal cartridge gun.
Resin
Resin