Can I force a client to use a specific AP?

[Bits4Brains]

I have two APs one is on the first floor the other is on the second.  My devices on the 2nd floor keep connecting to the downstairs AP and as a result my throughput is not as fast as when connecting to upstairs.  How can I stop the clients upstairs from trying to connect to the downstairs AP?

[AMP]

@Bits4Brains 

Association decisions are made solely by the client. We would recommend setting the clients roaming setting to aggressive. This will force the client to start looking for a better AP at a higher RSSI threshold. This setting is changed differently depending on the client. Our documentation outlines this further and how to adjust this on your device.

https://documentation.meraki.com/MR/WiFi_Basics_and_Best_Practices/Client_roaming_and_connectivity_d....

https://support.apple.com/en-sg/HT206207