Looks to me like your offset is wrong, or your first layer height is too large

Many suggest adding some type of adhesive to the surface, and I have a trick that might interest you. Glue sticks and hairspray are messy and are a pain to clean. When I used a glass bed, I kept about a tablespoon of sugar dissolved in little less than a cup of water nearby. One could use a paper towel to wipe a thin film over your glass bed. I did this as it warmed up and the water dried quickly, leaving a thin tacky surface. One could put it in a small spray bottle too. Very easy to clean with water. If you eventually get buildups after weeks of printing, a quick wash with soapy water cuts through instantly. Give it a try. I could never get PLA to stick to my glass bed. PETG worked sometimes, and other times it bonded too well and broke the glass when it was removed, or cooled to the point of removing. The sugar water worked there too in providing a sacrificial layer that protected the glass and made removal easier.

Hey man, your first layer isn't getting enough squish by the looks of it. It likes a decent amount of push into the bed compared to some other materials. PETG doesn't like as mush mash down as PLA. So if your printing PLA, try increasing your squish. You can do this via your z offset.

But do you really need your bed at 70? Mine runs and sticks just great at 60. 70 seems a bit warm for pla, as it keeps it just a bit too close to the glass transition temp for my liking. But if 70 has worked for you, then stay there.

But as another suggested, maybe raise your first layer temp by 5 or 10 and see if that helps. It might be that it needs a bit higher temp to flow better.

Hair spray is the way

Increase the temp on your first couple layers by 5°. I’ve found that really helps with adhesion. If you’re still having difficulty with certain prints try using a brim.

Is that just bare glass? I've never seen anyone have consistent luck getting filament to stick on that except when using hairspray or glue sticks. You'd be better off with borosilicate glass, or you could get a sheet of G10 and put a PEI sticker on it (unless you're using nylon filament). If you have a magnetic sheet on your bed you can also get PEI on spring steel.

Did you try putting anything on the surface to assist adhesion? Hairspray? Glue stick?

I've never had great success with glass. I know it's popular.

What's z your offset Calibration method? Have you run that lately? Mine is to print a 20x20 mm, filled-in square and see how good the lines fuse. There are many guides. Look for one that shows the pictures, like this https://www.anycubic.com/blogs/3d-printing-guides/how-to-fine-tune-z-offset

I was having trouble with my glass bed originally, to get it working nicely without glue or hairspray I:

• made sure the bed was very clean, I use rubbing alcohol to clean it
• dialed in my z offset, I usually match it to my layer height, so if I'm printing at 0.2mm that's what I set the z offset to
• upped my print temp a bit, I usually print at 205-210 with PLA

Maybe one of those will help?

On top of some of the other tips, layer height being the most prominent, perhaps try a different soap or clean it with alcohol after. I've noticed a difference between soaps (and even between toilet paper brands) - some things leave a bit of residu I think.

Those lines dont look flat enough to me. https://ellis3dp.com/Print-Tuning-Guide/articles/first_layer_squish.html

The guide is largely klipper oriented but has marlin instructions after the klipper instructions.

Other than that I've tried some samples of bed adhesion aid of different brands which help for printing some of the bullshit filaments that stick to literally nothing and they are much less messy than hairspray or glue and most didn't smell awful, but I haven't found them to actually be necessary for anything other than the really slippery filaments.

I use Window cleaner.