I have an i9-9900 (non K) running on my ROG STRIX Z370-i motherboard. Whenever I run an all-core work load that doesn't have AVX instructions (e.g., Cinebench R15), the CPU boosts to 4.6 GHz as it should. Whenever I run an all-core workload with AVX instructions (e.g., Cinebench R20 or Handbrake), the CPU will only boost to 4.5 GHz. I've used the Intel Extreme Tuning Utility to verify that an AVX -1 is being applied (although, it is grayed out so I can't change it).
I've looked through the UEFI BIOS pages from top to bottom, and I cannot find anything mentioning the AVX offset. I have the latest version of the BIOS installed (2401, dated 7/12/2019). Is there some other setting I need to change in the BIOS that will expose the AVX offset?