Purchased 5 of these devices to use as adapters between small embedded system and PC.
Had another (more expensive) USB->Serial adapter which works properly.
Driver installed fine and claims to be up to date version, COM port detected, speed set to 115200 as required by embedded system.
Traffic from the embedded system -> PC works mostly fine (some incorrect characters, but 99% OK)
Traffic from PC -> embedded system does not work at all.
Cross checked by swapping with other (expensive) USB->Serial adapter and it works perfectly.
Tried several of the received 5 units to check for single faulty unit. All showed the same faulty behaviour.
So at least in my use case, these devices don't work.
Will buy more expensive unit and put it down to being overly frugal.