Most cases where people think they are not earning coins anymore are actually not true. We suggest you take a note of how many coins you have now, and check after a few days to see if your coins are still the same.
If your coins are definitely frozen, there can be a number of reasons for that.
Unfortunately, we can't disclose what are the factors that impact your coins, but it can be due to things like you getting a warning on your profile, or our system detecting something on your activity that doesn't like. There can be a lot more reasons.
Please note that the speed that your coins grow can vary all the time, and if it is frozen for a while, that is just temporary and it should go back to normal after a few days, should you continue to be a good member on Similar Worlds.