Did I unknowingly damage my PC?

I am concerned that I may have unknowingly damaged my gaming PC when wiping it clean. I had just wiped my PC for a fresh start. I erased my SSD, and reinstalled my Windows 10 operating system. I have since noticed three things First is on start up. At the interval between the logo for my motherboard's manufacturer and the Windows start up logo, it use to have a black screen with a blinking white line at the top left of the screen. Now, I notice that the blinking line appears briefly near the center of the screen before moving to the top left before Windows 10 starts up, after that, Windows appears to be operating normally. The second thing I have noticed is when I am watching a movie on HBO NOW. The widescreen movies have grey lines above and below the picture instead of black. Third and finally, it looks as though the BIOS was reset when I reinstalled the operating system.

Now, even though, I built a gaming PC, I had no intention of overclocking the PC. I prefer to have a stable and reliable build running up to max factory settings. Please note that the components of my build are listed at the bottom of this post. When I built my PC, I selected RAM sticks rated at 3200 megahertz based on the advice of other builders. The intel i5-7600K was rated to support 2400 megahrtz. As I already stated, I had no intention of overclocking. When I had built and tested the system, I wanted to get the max factory memory speed. I was under the impression that there was no relation between the memory speeds of the CPU and RAM. Under the guidance of the representative of Gigabyte at the time, he guided me to adjust the RAM settings as followed to get their maximum memory speed:

M.I.T -> Advanced Memory Settings -> Extreme Memory Profile (XMP) -> Profile 1 -> F10 -> Select Yes.

I thought I made it clear to the rep that I was not looking to overclock and he made no mention that these settings were for overclocking. When I spoke with a Gigabyte rep today about making sure I had re-applied the correct settings, he stated that I was setting the PC to overclock. This has me concerned that for the last six months that I may have unknowingly damaged my PC. With regard to the BIOS settings, no other changes were made except for the steps that I just listed. With the exception of the Windows start up process and HBO NOW streaming, everything else appears to be functioning normally. The only error message to appear on my PC was after the first restart after installing one of the apps from the Gigabyte APP center, the message has not appeared after the following computer restarts. Besides that, I have not received any other error messages or blue screens of death. Everything else seems to be functioning normally.

The only other accessories connected to my PC are my Logitech G710 keyboard, G13 Game Pad, G600 Mouse, C922 Webcam, 60-Inch Sharp TV, HP laser-jet Printer, Creative Sound Blaster Omni 5.1 Sound Card, and an external hard drive connected via USB 3.0. I wish to add that a couple of the items on the list below were replaced. First, the WiFi antenna was replaced with an Asus USB AC68 antenna and the Asus Blu Ray Drive was replaced with an LG Blu Ray Drive. Also, a front mounted 4-port USB 3.0 expansion card was installed in my PC. The parts for my build are listed below:

Component Selection Price
CPU

Intel - Core i5-7600K 3.8GHz Quad-Core Processor
$221.49 Buy
CPU Cooler

CRYORIG - H5 Universal 65.0 CFM CPU Cooler
$42.89 Buy
Motherboard

Gigabyte - GA-Z270P-D3 ATX LGA1151 Motherboard
$100.88 Buy
Memory

Corsair - Vengeance LPX 16GB (2 x 8GB) DDR4-3200 Memory
$169.91 Buy
Storage

Samsung - 850 EVO-Series 1TB 2.5" Solid State Drive
$332.49 Buy

Seagate - Barracuda 2TB 3.5" 7200RPM Internal Hard Drive
$66.89 Buy

Seagate - Barracuda 2TB 3.5" 7200RPM Internal Hard Drive
$66.89 Buy
Video Card

Asus - GeForce GTX 970 4GB Video Card
Case

Corsair - 600T Silver ATX Mid Tower Case
Power Supply

SeaSonic - EVO Edition 850W 80+ Bronze Certified Fully-Modular ATX Power Supply
$92.99 Buy
Optical Drive

Asus - BW-12B1ST/BLK/G/AS Blu-Ray/DVD/CD Writer
$109.88 Buy
Operating System

Microsoft - Windows 10 Home OEM 64-bit
$89.89 Buy
Wireless Network Adapter

Asus - PCE-AC88 PCI-Express x1 802.11a/b/g/n/ac Wi-Fi Adapter
$108.76 Buy
Case Fan

Aerocool - Silent Master 200B 76.0 CFM 200mm Fan
$20.41 Buy

Aerocool - Silent Master 200B 76.0 CFM 200mm Fan
$20.41 Buy

Aerocool - Shark 82.6 CFM 120mm Fan
$9.89 Buy
Other

Rosewill RC-508 USB 3.0 PCI-E Express Card with 4 USB 3.0 Ports, Speed
$19.99 Buy
Total: $1473.66

I have always been careful in building my PC, I prefer reliability over absolute speed. Did I damage my PC? If yes, which components would most likely be damaged?

Thanks.