Try a hard reboot of your modem, unplug from the wall for 5 mins, then try again.
Another option is to clear console cache this can vastly impro e performance on xbox consoles.
There doesnt seem to be a mass report of connectivity issues which would identify a problem on Bungies end.
Sadly Destiny being peer to peer its alot more sensitive to even small connection instability.
While your speeds up and down may be fine there could be other things effecting connectivity, for example your isp could be performing maintenace, an accident or fire effecting signal transmission etc.
Or it could be the age of your modem, just last year I had to replace mine and I found it via connectivity issues with destiny, yet could play other games without noticing it.
Try the hard reboot of the modem/router first and clearing console cache, -blam!- it helps👍
Not sure then, doesnt seem to be a widespread issue for other players at the moment so nothing will be flagging Bungies tech support yet for isolated instances and they will likely just say to check similar things I have suggested.
Mere static speed readings count for little regarding connectivity issues so while it may seem every thing is fine your end, the actual stability of that connection may not be.