How can I fix the automatic gearbox shifting issues in my Audi 80?

I have been experiencing difficulties with my Audi 80's automatic gearbox where it tends to shift randomly and lags when changing gears. What could be causing this issue and how can I fix it?

It is possible that the gearbox's control module is malfunctioning. I suggest having it checked and replaced by a certified mechanic as it requires specialized tools and knowledge.

Check the transmission fluid level and condition. If it's low or dirty, it could cause shifting issues. Consider flushing and refilling the fluid or bringing it to a transmission specialist.

This could also be caused by a faulty solenoid or shift sensor. Have a professional diagnose and replace these components if necessary.