Trident Maple: Bud hasn't opened
Hi, I'm from Columbus, OH and My bonsai needs some help i think. This is my second year owing the trident maple forest bonsai. I bought it from online and it was doing great last year. Last year by this time all the leaves were out and grown. But there is not a tiny bit has came yet this year. I see the buds are there since winter but it hasn't opened yet and I don't see any progress. not sure how long it has been since its last re-potted, so i was thinking that it might need root pruning. So i talked a lady at garden center as seems to be knowledgeable in bonsai. She asked me to hold off on reporting or root pruning this year as tree might be in process of doing stuff. But she didn't see it visually so i wasn't sure. I'm asking for second opinion. Do you think its dead or has some issue? I do see that trunk is green from inside even i tried to open one of the but to see what going on and it was green as well. Has any experiencing this or has in past. I have attached some pictures.