I recalled Koodo home phone didn't support VoLTE so you would have to rely on 3G (UMTS) to make/receive calls.

In the User Guide for WF723 from The 101 on Koodo wireless home phone, on Page 9 the document stated the following, that is why I am puzzled by the change in colour Green vs Orange of the network/signal strength while receiving / making a call:

In the User Guide for WF723 from The 101 on Koodo wireless home phone, on Page 9 the document stated the following, that is why I am puzzled by the change in colour Green vs Orange of the network/signal strength while receiving / making a call:

 

As I mentioned earlier, it didn’t support VoLTE, so it had to switch from LTE (green) to 3G (orange). The color of the indicator was displayed correctly.

The ZTE WF723CA Wireless Home Phone (WHP) DOES support LTE, so does Koodo/Telus.

Anyway, I thought I had power recycled the WHP earlier this week.  However, I have forgotten about the battery.  Last night, I performed the following steps to properly power cycled the WHP:

1. Disconnected the phone,
2. Switched off the power,
3. Unplugged from the AC Adapter,
4. Removed the battery for 1+ minute
5. Put the battery back in and close the lid,
6. Connected to AC Power,
7. Connected the phone,
8. Switched on the power on WHP

Tested with outgoing and imcoming calls.  The signal status stayed green in both cases.

Will need to monitor this, as I read in another thread that the signal may drop back to UMTS on an older WHP unit.  See following thread:  https://community.koodomobile.com/tips-tricks-troubleshooting-232914/wireless-home-phone-volte-7817303

I think you were confused between VOLTE and LTE. The device supported LTE. Howeve, VoLTE only work if Koodo had provisions for it https://www.koodomobile.com/en/help/volte

Anyway, monitor the situation. Personally, it doesn't make much difference if incoming/outgoing calls work