Ender 3 Pro: adhering problems

I bought the Ender 3 Pro almost 2 years ago and have always had problems with the adhesion of the filament to the bed.
I have tried all sorts of tricks, including software levelling and running a code that moves to 9 positions 3 times and where you have the option of correcting at each position, and other methods.
The result was that I rarely printed successfully, but most of the time the nozzle dragged the filament around because it did not stick to the bed, no matter what the bed temperature.
So the printer has been inactive for months now.
I have decided to finally get it to print or definitely give up on it.
I am grateful for any other tips
P.S.: there are posts here that mention the Ender 3 Pro with the S1 add-on. What does this S1 mean?
With kind regards

Do you clean bed with alcohol, and paper towel? Having correct initial height is important too. Too much height leads to dragging filament around. The paper or feeler adds to initial Z distance, set in slicer.

I have only had sticking problem once. I did not have paper towel, and used tissue. I later found it was Puffs with lotion. I correctly cleaned with alcohol and paper towel, all was well.

I have a magnetic mat on the bed. Do you also print on a mat or on the bare bed?
Do you clean the mat with alcohol or the bare bed?​

The mat should be cleaned. I print mainly on borosilicate glass plate with special coating. It seems to hold well and releases when cool.

I will then try to print something again after I have cleaned the mat with alcohol.

But a clean mat is one thing, but at least as important is that the bed is properly leveled. What is the best method there?​

I’ve been 3D printing on an Ender 3 Pro for a little over 18 months. I started out using the included build plate and manual bed leveling. Results were so-so, sometimes I get a print that sticks then next one wouldn’t. About 12 months ago I switch to Creality glass. That was a big change and for the most part for the better. When It did stick it stuck really well and held on until the glass cooled then literally fell off the plate. If I was next to the machine I would hear a ‘clink’ and the model could be removed.

Then late last year I made my biggest ‘advancement’ by installing a BL Touch. That was amazing at how much it improved the success of model printing. But at about the same time I started having sticking issues with the glass. I tried washing it in hot water and Dawn, Using 99% IPA to clean the bed and finally had to resort to good ole glue stick to get prints to stick.

So on to a smooth spring steel PEI sheet. At first it was no different than glass, but after a lot of reading I took some 1500 grit sand paper and lightly scrubbed the PEI sheet and walla sticking is no longer an issue. Ever since the sheet has been a champ.

I did have a project that needed PETG and found it stuck too well so I did use glue stick for a release agent. I have since purchased a textured PEI sheet but have not tried it.

For TPU I am using the reverse side of the glass bed and am getting perfect results.

Bottom line I think the BL Touch was the game changer and then some minor changes to the print bed sealed the deal. I’m real happy with the models sticking to the build plate now.

Good luck

As @KitCarlson indicated the height of the nozzle above the bed is critical to good first layers. In case you aren’t aware, this is called Z Offset. I refer you to this video; I use it all the time to ensure I have good first layers:
[U]Best method for 3D printer bed levelling - YouTube
Also, with most firmware, it is possible to “live adjust” the Z Offset. So, for example, you could print one of the test squares shown in the video and, if the nozzle is too high or too low when you look at it printing, you can use the menu system to adjust the height a bit to correct the offset.

Thank you very much for your tips and for the link! I will get back to work with the printer in the near future.