Video lag is connected with sattelites and Google Play Services.
More sattelites = more lag.
If you disable or downgrade google play services CPU consumption will be 30% lower and video lag will gone.
You can test it by Cool Tool software (cpu usage).
If you downgrade map will work.
I tested it about one week ago and 'lastest' Google Play Services still caused a stuttering, however i do not remember a version.
I see here two people who claim it work with 8.1.15, Could you test it (check CPU load on cool tool), with disabled and with active google play service?
(you need to get about 15 satellites fixed to make a good test).
When 8.1.15 was released?
UPDATE:
I made a test.
With fw 1.4.10, DJI go 2.2 and Google Play Services 8.1.15 there is no video lag and cpu overload.