I received the Huntsman V3 Pro TKL (Firmware: v1.04.00_r1) today, naturally connected it directly to my PC and set it up in Synapse 4 (4.0.86.2504220800). After less than an hour, I noticed the following: A and D have different responses, which is also the case with other keys. After a while, Synapse said it needed 8-15+ GB of RAM. I tried reinstalling the driver cleanly, and I also tried reinstalling Synapse, but it still didn't help. After connecting my old Cynosa Chroma, everything is working as it should, so it's definitely a problem with the firmware or Synapse itself.
If there isn't a fix in the next week, I'll definitely return it, as it's not usable for me right now.