Speed limit

Hello, we were travelling back from Gatwick on Sat 070522 at midnight. When we got to the Maidstone services area the motorway was very confusing. We continued on the motorway to Ashford with Coned off lanes showing different speed limits. As we were on the inside lane we had to travel at 30mph. Yet on the 3rd lane it state 50mph on the signs. This stretch of motorway seems to be impractical now in both directions. The concrete barrier London bound makes it very dangerous and the coastbound 30mph limit makes it too time consuming.