What be the problem Matey

Points Scoring has halved or worse.

Midoki states the game can be shared on multiple devices, but this is limited to two devices. Sharing beyond two devices results in a massive drop in points achieved from battling opponents. 
This stops a team of players using one game account from scoring outrageously large amounts of points to become the monthly champion.
Like lots of things in the game, terminology is very important. Midoki seems to use “game installs” as a device! 
Re-installing your game on the same device within 48 hours of having played the game counts as two “devices” in Midoki language. If you happen to have your game on your phone and your tablet, and re-install the game on one (maybe because of some issue) you now have 3 installs, or 3 “devices” in Midoki language. As a result, battle points will halve. Adding another device will reduce points to a quarter of normal points, and so on.
The important thing for those in this situation is that tracking of devices using the same game account is over a 48 hour period, so your points from battle will return to normal 48 hours after play on only two “devices” is tracked.
This will only ever be an issue if you are playing on multiple devices and need to replace a device, or have some need to re-install your game. To avoid the issue: 

  • play on only one device for 48 hours before setting up your replacement device;
  • avoid re-installs where possible by seeking help from Midoki to fix problems before re-installing.

Replays aren’t correct

The replays aren’t like watching a replay on tv. 
The game servers don’t record each battle in a video format to be able to show it later on demand. What is recorded is where and when each pirate is released into battle, and when they use their special ability. The Artificial Intelligence of each pirate should then have them battle the same each time.
A “replay” is actually a “re-battle”, but a tiny error in where or when the pirates are dropped or their ability used can sometimes have a big effect on the way the battle finishes. It’s not uncommon for a three star win to appear as a one or two star win, and occasionally as a loss.
Rumble/battle points count only on the original battle so replay errors will have no effect on points.
Importantly, there is nothing wrong with your game simply because the replays don’t match with the original.