Curiosity asking - where did you buy them from?
Home Depot.
I have never seen a CFL instantly on with its max output, ever when its cold. If it was used recently and you turn it back on, you don’t have the issue. But if its been off for a while its a guaranteed 15-30 second wait for them to put out their maximum light.
They do come “on” instantly, but they don’t remotely give their max output instantly when cold.