You should RSSI rather than output power. Radios -> Pick your radio -> Advanced Settings -> set RSSI to a lower -ve number so if it’s currently -90dBi set it to -60dBi and it’ll boot the client off much quicker so it finds a stronger signal.
Im also seeing some recommendations around VHT values - please read up on what this does because if you force channel aggregation to can completely kill some clients.
Definitely DON’T use Auto for channels - it doesn’t work. If you have two access points in a detached house, set them on 1 and 11, VHT40 for 2.4GHz clients medium power RSSI -60dBi and soft kick enabled.
For 5GHz use channel 36 and 48 and VHT40 or VHT80 if ALL your clients are 3x3 (they aren’t so use VHT40). If it’s a big house use High power, RSSI set somewhere between -55dBi and -70dBi and move it lower if your clients don’t swap access points as much as you’d like. I regularly do home installs with an AP-AC-InwallHD in every room and UAP-AC-HDNano in the hallways and landings and we set the RSSI to -40dBi so the clients are switching from room to room. Unnecessary? Yes, but if you want to know EXACTLY where your kids are, very handy in a massive home.