XCTU version 9.9.9 for XBee3 Cellular firmware upgrade?

I’m using a XB3-C-GM2-UT-001 that is at firmware version 11620. I have XCTU version 6.5.13, which is the latest available at this time. I see that firmware version 11621 is available. However, when I attempt to program the new version through XCTU I get an error message that states: “The selected firmware is not fully compatible with the current XCTU version, it requires XCTU 9.9.9 or higher”. I checked the XCTU download page and I checked for updates through XCTU to confirm version 6.5.13 is the latest released version XCTU at this time.

Is this new firmware actually available? If so, how to I upgrade my module to test it out?

XCTU will not be updated. The XBee Studio is the correct tool for all firmware updates regarding any current Cellular product and newer. In this case, the 11621 firmware requires a specific updated version of the Telit firmware which also requires a specific installer. That option is only offered in the current version of the XBee Studio.