Click cup icon at lower left causes bleak.exc.BleakDBusError (Write not permitted)

[jmm5491]

Running Ubuntu 20.0.4, bluez version 5.53, Python 3.8. Current temp displayed. Battery % being updated in real time.
Actions:

1. Open the temp change popup and move the sliders to a different temp, close the popup. No change in cup temp observed.
2. Click on the cup icon at the lower left of the GUI.

Results: Python error messages with traceback as follows:
Task exception was never retrieved
future: <Task finished name='Task-95' coro=<MainWindow.setToTemp() done, defined at /synology/jmarks/src/python/EmberControl-main/main.py:108> exception=BleakDBusError('org.bluez.Error.NotPermitted', 'Write not permitted')>
Traceback (most recent call last):
File "/synology/jmarks/src/python/EmberControl-main/main.py", line 113, in setToTemp
await self.connectedClient.write_gatt_char(TARGET_TEMP, newtarget,False)
File "/home/jmarks/anaconda3/envs/ember/lib/python3.8/site-packages/bleak/backends/bluezdbus/client.py", line 856, in write_gatt_char
assert_reply(reply)
File "/home/jmarks/anaconda3/envs/ember/lib/python3.8/site-packages/bleak/backends/bluezdbus/utils.py", line 23, in assert_reply
raise BleakDBusError(reply.error_name, reply.body)
bleak.exc.BleakDBusError: [org.bluez.Error.NotPermitted] Write not permitted