Hi - picking up from your other thread - I think it started after you did a cage clean and then he was at your gf's nan's house while you were on holiday and then moved back to your house again. As mentioned - our last Syrian Charlie started bar chewing after we left him somewhere while on holiday and it took a good two weeks for him to settle down.
I think it's the big change of environment twice. We had to start going to bed early and turning the lights out as he stopped when there was no-one there. Also letting him out more. In the end, what did it was - a full cage clean. The cage smelled of the last house he had been in I think. Normally a cage clean can stress them, but in this case, it helped him settle.
So I washed the base and the bars, put all new substrate in, and added some new toys and chews as you have done, and this distracted him out of the stress, plus his cage no longer had scents from the house he'd stayed in.
The problem at the moment is maybe that he is stressed, and adding new things (more changes) is stressing him more. He needs to settle again. Try letting him out more in the evenings, or put a playpen up round the cage and leave the doors open (with a ramp down if the cage is high up!), but if he starts when he goes back in the cage, then just turn the lights out and leave the room.
Now you've added some more toys, I wouldn't move or change anything for a while and let him adjust. Keep talking to him