An 880 Cameo has 2 single speed pumps
The 2 single speed pumps have no bearing on the flashing FLO issue
When the heater shuts off and you get the flashing FLO error, does the circulation pump stay running?
If so, check the flow switch to make sure it is making good contact. If it is, make sure the pins are pushed all the way into the plug that goes into the circuit board. If those are fine, and you are still getting the flashing FLO error, you may have a defective flow switch.
If the circulation pump shuts off when you get the flashing FLO error, you will need to get a meter and see if the circulation pump is getting the correct voltage. If the circulation pump is getting the correct voltage, and it is off, there is an issue with the circulation pump.
I assume you installed a 230v circulation pump?