Stop using an unstable or uncertain installation and obtain appropriate assessment. A fitted hob should not be treated as a loose countertop appliance.
What the observation means
Movement can affect seals, supports and concealed connections. Pressing it down or adding weight does not establish that its fixings are correct.
A useful next step
Record when the movement began and any worktop changes. Do not pull it out, tighten hidden clips blindly or apply adhesive as a repair. The appliance and installation should be checked together before normal cooking resumes.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.