CRV3N

Little Update.
So Finally got the Weco Battery BMS to communicate with the Deye. Large thanks to @GreenFields.
For any further interest out there, this is what I did:
Connection is between a Deye 8kVA SUN8k-SG01LP1-EU and a WECO 5K3-XP
Battery Dip Switch 7-on and all others off-position (reset battery for changes to take effect)
Access battery settings using WeCo Bluetooth app -> select inverter protocol 00CAN (there is a Deye protocol but I used 00CAN)
Battery side CANbus pinouts ->
Pin 1 - Can H -(red)
Pin 2 - Can L - (blue)
Pin 3 - GND - (green)
Deye Inverter side BMS port pinouts ->
Pin 4 - Can H
Pin 5 - Can L
Pin 2 - GND
Inverter settings ->
Under battery settings, select lithium and activate
Under battery settings, Lithium mode 00

Little Update.
So Finally got the Weco Battery BMS to communicate with the Deye. Large thanks to @GreenFields.
For any further interest out there, this is what I did:
Connection is between a Deye 8kVA SUN8k-SG01LP1-EU and a WECO 5K3-XP
Battery Dip Switch 7-on and all others off-position (reset battery for changes to take effect)
Access battery settings using WeCo Bluetooth app -> select inverter protocol 00CAN (there is a Deye protocol but I used 00CAN)
Battery side CANbus pinouts ->
Pin 1 - Can H -(red)
Pin 2 - Can L - (blue)
Pin 3 - GND - (green)
Deye Inverter side BMS port pinouts ->
Pin 4 - Can H
Pin 5 - Can L
Pin 2 - GND
Inverter settings ->
Under battery settings, select lithium and activate
Under battery settings, Lithium mode 00

Warning/Disclaimer: I'm not the installer, just the user. No real idea what was done, but I was also an unhappy customer at first, hence the phrasing "since installation was complete, I have had no issues with it."
That being said, short of calling up a local dealer or competitor, for my 2c I reckon you can get a few steps further using page 9 here:
PowerPoint Presentation (squarespace.com)
Pages 88-91 here:
0.5_5K3+XP+2022+EUROPE+Installation+and+User+Manual.pdf (squarespace.com)
and downloading software here:
Software - WECO Batteries
and maybe until you've got it figured out, set up Voltage mode in the inverter manually using the data on the side plaque of the battery to give the customer at least some usage of his system.
Hope this helps.