I'm having trouble with an electric dryer.

It spins and heats, but doesn't get up to full temp. Outlet temp is only about 87F on high setting.

I've cleaned it thoroughly, vent is unkinked and clear.

I took the panel under the door off and can see the heating element glowing, but it only does this for a short time then turns off and cools down. It does eventually start again, but doesn't ever get up to 150 at the output.

It's a stacked Whirlpool thin twin, model LTE6234DQ2

Thanks for any help!