What is the most common cause of transmission failure in a Vauxhall Insignia?

I've noticed my Vauxhall Insignia is having trouble shifting gears. What could be causing this and how can I fix it?

Transmission fluid may be low or contaminated, causing issues with gear shifting. Check the fluid level and quality before considering more serious causes.

The shift solenoids may be malfunctioning, impacting the timing and smoothness of gear changes. Have a professional inspect and potentially replace the solenoids.

Worn or damaged transmission mount can lead to misalignment and difficulty shifting gears. Look for signs of wear and have it replaced if necessary.