I can clearly see the white erase marks in your bubbles. You mention in your postscript that you think you over-leveled your scans. As an editor for the LWB scanlation group, I can say with absolute certainty that your scans are actually underleveled. I'll show you how the page is supposed to look below:
This is how page 2 is supposed to look, properly leveled (from the RAW) Top half: /img/e-hentai/HBIrv/c2c4154414.png Bottom half: /img/e-hentai/HBIrQ/ac4f371c7b.png Here's the leveling histogram, provided you use Photoshop: /img/e-hentai/HBIsy/53fd3ac9f0.png
Don't feel bad. Complicating the leveling process was the amount of dust on the scans themselves. The points where I would normally leave my leveling markers on still showed a lot of dust on both black and white surfaces, so I had to eyeball the scans and increase the levels until they were clean enough. If I kept going and tried to level all the dust away, I would've over-leveled my scans and completely ruined the fine details, including linework, so I stopped when there was just a faint bit of dust around the edges. Generally speaking, speech bubbles are supposed to be 100% white. If your bubbles are any other color besides white, you need to level your scans more. If you can clearly see the white brush tool marks inside the non-white bubbles, you need to level your scans more.
http://www.zff.co/BhvgY which is how I learned to level my scans when I was first starting out on editing.
https://ouo.io/gxicYL which is the URL that the above page comes from.