Thomson Hygrocapt Air vented dryer (anti-crease)?

I position my timer to 90 minutes for tumble dry but after two minutes of tumbling, it stopped back at 90. I try using another timer at 99 minutes and it tumble dry for two minutes and stop also at the timing of 90 minutes. For other timing for dry clean, it works at 20 or 40 minutes but not for 90 or 99 minutes.

Can you please help me. This is confusing. I do not want to waste my money and buy another dryer.