Five minutes into my first ride with this new device, all of the external sensors disconnected at once and would not reconnect. The sensors included a Poalr HRM, a SRAM AXS shifters and a SRAM Quarq power meter.
This is a variation of a long term, never solved problem on the Edge 1030 Plus, where the sensors would disconnect and reconnect, leading to lots of beeps and messages on the older unit.
When this happened on my Edge 1040 all the data fields displaying external data went blank and did not recover. The data fields provided by the 1040 like temperature, time, distance and duration continued to be displayed directly. As noted, this was just minutes into the first ride with the new device. The device is completely up to date - I made sure that it was updated via Garmin Express before I started the ride. This is extremely disappointing that Garmin released a device with serious bugs that render it basically unusable.