I attempted to climb to FL400 at a 37,000lbs gross weight, but I was well under 100fpm climb at about FL390. This was using a climb profile of 250/M0.72 at -10 ISA. I descended down to FL380 and accelerated to M0.80 with no problem. I decided to climb back to FL400, and I'm managing to maintain FL400, but I'm only able to accelerate past M0.72. This should be possible at this GWT, ISA, and climb profile according to the Operations Reference. I crosschecked this with a CL604 QRH and I'm seeing similar book numbers. I double checked the GWT in the XP default W&B menu and it only differs by a couple hundred pounds. I just wanted to report this to make sure this isn't a bug. Thanks again for the wonderful aircraft!
EDIT: I saw the comment Toto made to a similar issue about maximum N2 in regards to TAT. However, it seems that if I disconnect ATS and go to max power, I'm not meeting that close to the maximum N2 shown in the chart. Perhaps this is why I'm struggling to accelerate? I was seeing about 87% N2 maximum when I should be seeing around 90% N2 maximum for the given TAT.