I had one full year of GDFL subscription in 2017. Trust me. The data has issues during live market and the issues disappear later in the day during backfill wondering what went with strategy during market hours. This happens intermittently but can cost you huge at times. I had put lots of log to verify the same. I had even reported to GDFL. Infact after paying for one full year subscription plan, I stopped using it after 6 months. Why pay so much if they offer same quality data that other providers like true data, share guru offer in less cost. Even better to use free open source like RTD to pull data from nest for intraday.
I even got people from a big algo platform company involved but nothing worthwhile happened.
Either it is a deliberate (which makes it a mini scam) or technical issue (in sufficient hardware to support all connected clients)
99% of all IT support engineers in all of these companies only know one solution to all problems .... Uninstall & Download again and Re-install.
Any customer who wants different support is politely (or rudely) shown the exit door.