It is not yet clear whether the matter is in volume or in the relatively new USB 3.1. I decided not to take 64 GB flash drives for now, because two USB 2.0 32 GB flash drives from this manufacturer still work fine.
32GB SanDisk USB Flash Drive (SDCZ430-032G-A46)
78 Review
Kingston DataTraveler SE9 32GB USB 2.0 Flash Drive for Reliable Data Storage (DTSE9H/32GBZ)
69 Review
Samsung BAR Plus 128GB USB 3.1 Flash Drive - 400MB/s - Champagne Silver (MUF-128BE3/AM)
65 Review
Samsung BAR Plus 128GB - High-Speed USB 3.1 Flash Drive Titan Gray (MUF-128BE4/AM)
67 Review
2 TB External HDD Western Digital WD Elements Portable (WDBU), USB 3.0, black
84 Review
Shock-Resistant Transcend StoreJet 25M3 USB 3.1 Slim Portable Hard Drive with 500GB Capacity
99 Review
🔜 Seagate Backup Plus Slim STHN2000400 2TB Portable Hard Drive - Black: Your Reliable External Storage Solution
93 Review
2 TB External HDD ADATA DashDrive Durable HD650, USB 3.2 Gen 1, Blue
55 Review