I searched Google for "Freezer Not Cold Enough" and came upon the AppliancePartsPros website. It took only a few minutes to find the repair video at https://www.appliancepartspros.com/whirlpool-start-dev-w10613606-ap5787784.html, which mentioned the clicking sound, so I ordered the Compressor Start Device, received it in 2 days, and just like in the video, I replaced the part in 15 minutes. Problem solved!