Some usbs drive fail to open on newest computer only

Have you tried a AC power USB hub? If that doesn't work that laptop either send it back or have dell service it. Faulty MOB (motherboard) with attached USB port gone partly duff (bad).
 
You may be stuck between the rock and the proverbial hard place.

While there's indication it could well be a software issue (ie driver filters and perhaps also the apps they support), IMO still can't rule out hardware.

Problem is: even if it's the Dell and/or the ST Micro driver filters interfering with your Lexar... I'm guessing you still need them for the features they support: Disk Encryption and Free Fall protection

I had a similar h/w vs s/w issue once. What I did: Take the laptop to a local computer store, tell them you want a secure flash drive you can verify works with your Dell. If it works, you'll buy the flash. Otherwise, you'd be returning it. In which case, they should let you try one in the store to check it out and saves you and them the hassle of the return

Plus, if another vendor secure flash works, you're good to go. If NOT, you can go yell at Dell!
 
3 more things that didn't help:
reformatted one of the flash drives
changed the drive letter in Disk Management, after booting up with the drive in place
disabled all the startup programs, per SNGX1275's suggestion above

I like your suggestion to take the laptop to the store and ask to try out drives there.
 
An update and thanks.
I got a new SanDisk flash drive that works with the laptop and has the features we need. It's still unclear what the issue is with the two Lexar drives. Lexar had no useful suggestions and I'm still communicating with Dell. It's no longer a priority but I'd like the mystery solved so I can be certain how to avoid it.
Anyway, thanks again for all your suggestions. They helped to narrow the issue and at least increased my technical knowledge.
 
Thanks for taking the time to provide the update. Glad to hear you at least have another device that solves your problem! :) (y)
 
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