Lsw3-15-ffff-1.0.84 !!better!! -

The log says: ffff – full overflow, but not an error. More like a door left open.

Fixing connection drops between the inverter and the app.

Thus, most plausibly describes: "Firmware version 1.0.84 for a Layer 3 Switch, 3rd generation, 15-port variant, with full feature mask (ffff)."

The number is likely indicative of the hardware series or port configuration. In the realm of network switches, numbers often correlate to the number of physical ports.