On a perfectly horizontal, smooth surface without friction a Gömböc will always return to its single stable equilibrium position. Yet your Gömböc has a highly sensitive geometry. Non-zero slope, uneven, rugged supporting surface and wear, scratches and other damage on the surface of the Gömböc surface may result in additional stable equilibria. Even dust on the surface can impact the characteristics of a Gömböc.
In most cases, defects of the Gömböc surface can be corrected only by using technologies which are more expensive than the production of a new Gömböc.
Based on the above, we suggest that you handle your Gömböc with utmost care and safeguard it against mechanical damage. It should not be exposed to temperatures above 50 Centigrades. We suggest cleaning the surface with a soft cloth that does not cause scratches and only using neutral cleaning liquids.