background jitters 2D 8-bit pixel art game

Hello I'm a beginner and I'm very confused! Please help! I'm attempting to make my first 2D game. It is in the style of classic 8-bit MegaMan. everything seems to be lined up perfectly. (for example) I imported a very large texture background 4107x1192. It is an actual "ripped level background" from Megaman 2. I'm using Unity's new Tilemap system and I aligned the background with the Tilemap grid so that each tile aligns perfectly. I also resized my Orthographic camera size to "7" so that it was perfectly aligned with the height of the background. All my sprite sheets are NOT power of 2 textures.. but every sprite is set to 16 PPU. I can see that every sprite, including the background are all scaled properly in proportion to each other.

Now, everything seems to be lined up and scaled perfectly but, when the camera follows the player. the background jitters, kind of appears to be flashing in brightness, and I can see that pixels are being "squished" (for example, a single pixel in my sprite art takes up 3 pixels on my 1600x900 monitor, but as the camera moves it keeps changing from 3 pixels to 4 pixels (squishing) if that makes any sense.

I've tried using "GGEZ Perfect Pixel Camera" asset. It helps with the "squishing" effect. But it decreases the camera size to "6" and cuts off the edges of my background.

Do I need to use all power of 2 textures for my sprite sheets?

Any help or insight on this issue would be greatly appreciated! Thanks in advance.