After Heat shuts off, all zones turn on and fan keeps blowing forever

[rudypooh6]

I moved into a home this past summer that has an older (mfg 2010) Bryant system (FBCNF036T00ABAA) heat pump with 5 zones controlled by EWC BMPlus3000 rev B (IC sticker says BMP3000 ver 2.9) and each zone has a Robert Shaw RS4110 2T thermostat. Dip switches on the thermostat are set to "ELEC" and "NONHP". I have attached images of these items.

Over the summer, the AC has worked great. It cools well and the damper controls for each zone all work as expected. yesterday I turned the system to heat for the first time. I set all 5 thermostats to heat. When the heat came on, the system heated up the home great. No issues getting warm. Outside unit came on as expected, etc. However once the setpoint was hit, the outside unit shut off as expected but the fan and inside system seemed to keep running indefinitely. It kept warming all zones and showed no signs of stopping. Eventually when temperature was 4 - 5 degrees over setpoint on all zones I hit the reset button on the EWC panel for 7 seconds to reset the CPU and the system shutoff as expected.

At this point, I ran a little experiment. I purposely set all zones to well below the current temperature so that the heat would not come on. It did not, as expected. Then, I set one zone so that the heat would come on. It did as expected. I observed the zone dampers function as expected - all zones closed except the one that was set to come on. I observed the LED's on the EWC show the correct zone lit up, the others off. The heat came on as expected (inside unit/fan and the outside unit).

Then, I set that zone to a setpoint so that the heat would shutoff. I heard the thermostat "click" and the outside unit shutoff as expected. However, the inside unit/fan did not shut off. Then in a few moments I observed all of the zone dampers open so that air could flow to all zones. the LED's on the EWC indicated this as well. At this point all zones LED's were lit, and the "B" LED was lit indicating the reverse valve was energized. It seemed at this point the fan would keep blowing air to all zones indefinitely - similar to what I observed the first time I used the system.

Again I pressed reset 7 seconds and it reset the CPU and everything shut off as expected.

I'm hoping someone has a suggestion to check? Since the AC worked great and had no issues with zone control - I'm thinking/hoping it might just be a setting that I need to change to get it to work properly wtih heat turned on. I also was suspicious of the thermostats being set to "NONHP" since this is a heat pump system. But the EWC manual says you can use both HP and NONHP thermostats with it. I did confirm the dip switch on the EWC is set to "HC" for a traditional nonHP themostat.

Thanks in advance!