Microsoft has made changes to their Windows 10 settings. This may cause a decrease in performance when using a Thunderbolt™ 3 SSD Enclosure. Below are steps you can take to resolve the performance issues until such time as Microsoft resolves any comapatibility issues.
Device Manager > Disk
Enable the write caching to bring the write performance back to normal levels.
Please note: By making these changes, it is very important that you use the proper steps to disengage the SSD Enclosure to avoid data loss on the drive.