It's not the Roku - its the Crestron's control of the Roku via IP (Roku's ECP) causing this behavior (especially considering both of your Ultras have behaved the same way in the same IP control setup with the Crestron).
The Crestron (or its Roku remote control module specifically) is likely "spamming" the Roku with control commands and the Roku is simply responding accordingly. You need to contact Crestron about either updating the firmware/Roku control module or reconfiguring the specific control sequences/timings for Roku devices.
