SanDisk Cruzer 256GB Will only accept 26GB of files

Recently purchased 3 SanDisk Cruzer’s, each 256GB; I wanted to store videos on them, 202 GB on each Cruzer. HOWEVER, when attempting the first file transfer, it will only accept 26.1GB…one-tenth of stated amount. What’s the issue??  Is this possibly a situation where I need to reformat the flash drive to format other than FAT32??  If so, and assuming I attempt to try changing the format, will this in any way affect my PC and/or the Windows 10 loaded on it?  I’m not hugely computer savvy, but surfing the internet gave this as an option, but want to make certain I won’t change anything on my PC.  Any advise/help someone can provide would be greatly appreciated.  Thank you.