When I try to open the gate, the motor “buzzes”, but it appears it cannot manage to open it. What is happening?
It may be mechanical friction of the gate itself due to wear, or deterioration of the start condenser (for 230V motors). In the first case, you can try to unlock the motor and try to move it manually (you will realise as it is more tiring), while in the second case you should ask your installer to check. In both cases, you should however ask the installer to intervene to solve the problem.