We will need more information if we're to help you out. Here are a few points to start with:
1. What version of Photoshop are you using, exactly (like 19.0.1)?
2. What OS version of High Sierra (like 10.13.3)?
3. You mention a Wacom tablet, are your drivers updated? What version?
Now, about the specifics of the brush lag problem:
4. What is the dimension, in pixels, of the image you have?
5. What is the brush size? Are you using a regular brush, a mixer brush, an erodible tip?
6. Does the lag occur on a brand new image, small size (i.e. default Photoshop size) with a small ordinary brush tip?
If you're working with a very large image, and/or your brush size is very large, lagging will be a problem for sure.
1. The version is 19.1.0
2. High Sierra version 10.13.2
3. Yes, the last version: WacomTablet_6.3.27-2.dmg
4. 248 x 343 pixels. In fact any dimension
5. Any brush size. Although the pencil works well. Regular brush. I have a video, where can I send it?
6. Yes the lag occur on a brand new image, on default Photoshop size, any Origen and image size with any brush.
No, no I don't use a big brush size or very large image... I don't know why.
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I wonder if you unplug your Wacom tablet and try the mouse only, do you still see the lag?
If so, can you try after disabling "Use Graphics Processor" under Photoshop Preferences > Performance? After disabling, restart Photoshop and see if you still observe the lag.
If that doesn't work, I would consider resetting Photoshop preferences to the default under Photoshop Preferences > General > Reset Preferences on Quit