XL - upload of *.bgcode fails  

XL - upload of *.bgcode fails

Hello,  I've recently purchased an XL (5 tools head option) having used the 2 MK4s I have for around a year with great success.  I'm having a 'weird' issue on the XL in that when I try and load any .bgcode via the network the upload fails almost instantly with an 'upload failed message'.   The XL and both MKs are wired into the same network, no WiFi involved and I'm generating the bgcode from the slicer on the same laptop that I would upload to the MK4s.     I dont have the issue on the MK4s and uploads via the network work just fine, although while printing on the MK4s  the web page for printer, goes into a 'page not found' status, if you leave it long enough or at end of print it eventual sorts itself out (if impatient) a quick reset sorts this issue.

The strange/weird thing is if if I take the bgcode file I tried to upload via the network on the XL and put it onto a USB stick and put the USB stick in the XL - it will print quite happily which suggests the bgcode is ok. I tried turning off the 'validate bgcode' option on the XL but that made zero difference.

Anyone seen this issue or offer any sage words of advice here on what the issue might be as this is making me nuts!   I've scanned the forums and used our friend Dr. Google.....I can see 1 or 2 others have had same issue, but no mention of a solution that I could find.