Using Advanced Startup in Settings to boot from USB resets pin

This has happened on a few occasions recently in the past few weeks on 3 separate computers being worked on. I boot off of a USB to do a memtest. I use the Advanced Startup section in Recovery in 10/11 and choose to boot from the USB in the Recovery Environment. Once the tests completes, I boot back to the login screen and the pin has been wiped and has to be re-set up. I'm wondering why it does this and how do I mitigate this as I routinely test machines memory from the USB? On the most recent machine, it has caused a massive issue as my customers rarely know their passwords. So now were are going backwards trying to reset passwords to be able to get codes (which also don't work because it says "Try another verification method..."). It has become one hurdle after another. My assumption is that it is tripping Secure Boot, but if I'm initiating this from within Windows, isn't it declaring the USB "Safe"? I'd rather not have to turn off Secure Boot every time like I used to in the past, but I haven't had this issue until recently.