I am absolutely fine with using it as just a BT speaker, however I can't even do that because it won't let me connect it to anything without setting it up through Cortana first, and Cortana setup won't work on three devices (W10, iPhone, iPad) because...
well, it's Microsoft.
Basically, with the sole exception of Xbox, anything that is consumer oriented and MS branded is guaranteed to be killed off after a short while. Only a fool would invest into MS ecosystem at this point, outside of Windows / Office. What a disaster.
Time to pack that nice Invoke and dump it into trash.
Don't do that it yet.
I had the same issue after 6 months of keeping invoke in storage while moving.
Cortana is not recognizing it in the last step "Something Went Wrong"
I tried something else - instead of Cortana I went to my "WIFI" settings of the phone and found invoke under Accessories. Connected to it and it redirected automatically to join the wifi.
So, try setting it up as an accessory directly instead going through cortana.
After that at least it started working as a Bluetooth device successfully making it more than a paper weight.