First, make sure you have the latest BIOS version installed, which was released two days ago, and then re-try with the new BIOS version. That version specifically addresses memory improvements and compatibility.
https://www.gigabyte.com/us/Motherboard/TRX40-AORUS-XTREME-rev-10/support#support-dl-bios
G.Skill does not even show that memory kit as being compatible with your motherboard.
I would look to one of the kits seen at the following link. All of which show to be compatible with your motherboard. G.Skill does not list ANY 128GB 3600mhz kits as being compatible either, so it looks like you are likely limited to 3200mhz if you want something from G.Skill. They show four 4 x32GB kits as being compatible, all of which are 3200mhz kits.
G.SKILL
www.gskill.com
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Also, looking at the QVL list for that board, but also understanding that it is not a full validation list of all memory that can or will work with that board, I do not however see more than one memory kit shown to be capable of providing 128GB and that is only for a single Adata memory kit using 4 x32GB DIMMs but that is only at 2666mhz with XMP verified. No other kits show on the QVL that are above 2666mhz AND provide 128GB. You may be able to mix two 64GB kits together but given the fickle nature of all these AMD platforms when it comes to memory support, you are likely much better off going with something from the G.Skill memory configurator validation page.
Mixing memory kits is sketchy under the best of circumstances. Even more so when talking about Ryzen and Threadripper. Try the BIOS update first and see what happens. If you have to, or plan to buy a kit, I'd stick with what G.Skill says will work. Corsair does not even seem to list any of the TRX40 boards on their memory finder pages.