Thank you very much for the interest shown by everyone who has sent their answers.
I think I have not explained well the issue. Now, there it goes (I hope better explained!):
I have a 16-inch MacBook Pro (2019), I have installed the Big Sur 11.0.1 operating system, I have installed the R 4.0.3 and the R GUI 1.73.
The R works fine, I think it is a problem with the R GUI.
When I open a session in R, I get the following warning:
2020-12-03 11: 34: 43.708 R [2479: 145386] Warning: Expected min height of view: (<NSPopoverTouchBarItemButton: 0x7fb0d3e23aa0>) to be less than or equal to 30 but got a height of 32.000000. This error will be logged once per view in violation.
And from that moment, the management of the windows in R and the computer slows down.
Also, every time I open a new file in R (in the same session), the warning appears again.
One of the messages I received on this mailing list said that it could be a problem related to the TouchBar of the MacBook Pro.
I have tested the same R and R GUI on a MacBook Air (Retina, 13-inch, 2020) with Big Sur, and, indeed, that problem does not appear.
I know that in Terminal and RStudio there is no problem, but I would like to solve this issue, since I prefer to work with R and the R GUI in a Mac, instead of Terminal or RStudio.
Thank you very much for your attention.
Sincerely,
Mar?a-?ngeles Casares-de-Cal