Your location has Strong Signal Strengths , the Tv transmitters are Close.
Strong Multi-Path reflected signals are the Situation/Problem at your location.
Digital Broadcast Tv tuners can correct a certain amount of multi-path and then at some point the multi-path amount will be more then the computer in the tuner can correct.
The result is picture and sound drop outs and no picture and sound.
Using a amplified antenna or external amplifier will amplify the multi-path , stronger multi-path means Worse Reception.
I recommend a Non amplified directional antenna for reception.
A directional antenna will reduce the multi-path and improve reception.
Put a , Antennas Direct , CS2V , UHF/VHF antenna , in/at the window.
C2-V-CJM ,
www.amazon.com
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Digital Broadcast Tv Tuners can develop - Digital Glitches - that are not cleared out with simple channel scans.
To clear tuner do Double Rescan.
www.wchstv.com/DoubleReScanAlert.pdf
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So is this a , house , town home , condo , apartment , mobile home , motor home , or etc.??
What floor??
What is the top floor??