Heavy lag in moving, opening chest, mining...

Good morning. Since a few weeks my friend and I are experiencing heavy lag and disconnections from the Minecraft Relms he owns. This happens both if only one is in game and if we are together. We both have good and stable internet connections (25\30mb), checked multiple times.

Some non-exaustive examples:

• walking a few  blocks and then being suddently taken back, like the game lagged and did not tracked my movements

• destroying blocks (like mining) and then being "taken back in time" with the blocks not destroyed

• right-click on a chest to open it, it may took from 2-3 to 7-8 seconds to open

• sudden disconnections with various message: connection lost, internal exception

The above problems may occur constantly, or once in a while during play, or a time or two and then everything is smooth for some minutes... There is no clear behaviour in this.

I appreciate any help you can give us in this, we are paying for the realms server and in this conditions in unoperable.

Thank you

kind regards