Stop Light/turn signal blowing bulb

how long do the bulbs last? and are you buying the cheapest one or decent one

By blow do you mean one or both of the filaments are broken or are they intact but just not working?

Bad or marginal ground can cause this issue.
Or even lose fit in socket.
Back when I ran incandescent bulbs in truck taillights I would put a half pea sized dab of silicone on the glass near base. Old hands said it helped, absorbed vibration before it got to filament. Seamed to help.

Wrong bulb number? Same bulb as the right side?

Check the light socket for corrosion. Maybe the bulb is OK......

I little vinegar on a q-tip does a great job cleaning contacts.