- Did you use the correct lubricant (-> I.3.)?
Please notice, that many "biycle lubricant" like grease for chains and others are completely inappropriate for a planetary gearing system.

- Did you fill the whole drive with grease? In this case, there is no other remedy than opening and cleaning the inner life.

- Or try SFR Superior Friction Reduction - Spray! Designed for very low temperatures, SFR may help if grease causes too much friction.
And is ideal for arctic temperatures (to be used together with MoS2-grease).

- Or try some good bicycle oil with low viskosity. Don't do that over your expensive Persian carpet, as drive may leak, if lubricated with oil.