My Octavia (reg 10) has developed a habit in which the alarm goes off and lights flash after parking and locking, not  every time but often

Suggest you post this in the MK2 forum.

Easy fix. You see the sensors in the ceiling next to the courtesy lights....they get dust in them. Get a hoover and GENTLY hoover out the dust.

13 hours ago, roger191141 said:

My Octavia (reg 10) has developed a habit in which the alarm goes off and lights flash after parking and locking, not  every time but often

Er, that's what it's there for! As @varaderoguy says, with the added note that I use a keyboard vacuum powered by 2xAA cells (also for cleaning keyboards, PC vent grilles...)

On 14/02/2024 at 19:52, roger191141 said:

My Octavia (reg 10) has developed a habit in which the alarm goes off and lights flash after parking and locking, not  every time but often

 

This can also be an early sign that the alarm system has reached end of life and must be replaced. Skoda recomend changing the alarm around 6-7 years.

If you leave it as is, the next stage is waking your neighbours during the night.

End of life can be caused by the internal battery failing or the battery oozing out corrosive liquid which damages the printed circuit board.

See the thread on the alarm in ths sticky section of this forum.