DFU OTA issues with NRF51822

Hello there,
We have been using the same DFU OTA service for 2-3 years, and back in August/September a new version of NRF Connect came out and now when trying to update firmware using OTA, the whole process crashes.
I have reverted to an older version of the nrf connect app (pre update) and the process works fine, so I am presuming some update in the app has messed with this process. The DFU service is an old version, so maybe they have stopped supporting it.
Below is how this process works and where it goes wrong.
To upload the firmware I open the nrf connect app, connect to the device and open the Device Firmware Update Service, and click the up arrow symbol next to DFU Control point

This brings up the following dialog


I select the Application (0x04) option and click send. Then going back the scanner I locate the device now called DFUTarg


I then click the DFU symbol in the top right, which brings up the following dialog box


I select the Application option and click OK, I am then prompted to select firmware file. Once selected a dialog box pops up asking for an init packet

Here I select a file we use called “firmware_init.dat”. The graph showing the upload process opens but never goes past 0%, and the device shuts off. I have also included the error log from the app from this process.

I have posted this on the nordic forums and the support over there recommended use a BLE sniffer to monitor the process I have attached the logs from this process, but I am struggling to upload that here on the forums.
The support there also suggested posting here for help too.

Has anyone encountered this or have any advice?