Help!!! 😣

Model Number:
Brand: Brand
Age: Less than 1 year

Model Number: DV45H7000EW/A2
Brand: Samsung
Age: 1-5 years

Hello, I have a Samsung electric dryer, it started not drying our clothes, so I cleaned it thoroughly, replaced the whole heating element, fuse, and thermister unit. Now, it runs for 7 seconds and shuts off, and i have an error code which looks like an upside-down F and E, also, the low temp setting doesn't let me select it, and when it runs the cooling light stays on all the time.