Problem with viewport in Maya

Hi everyone,

I have an issue with my sides and front viewports in Autodesk Maya 2020 :

https://prnt.sc/stv2tg

As you can see, I'm able to see my object in the perspective viewport but not in the other 3 viewports (sides and front), they are juste completely gray... I tried pressing F or Ctrl+F or Alt+F and it didn't work :( I also tried to go to "View"->"View along axis"->x or another axis and it didn't work either. I did close and reopen Maya several times (and I also restarted my computer). I've had this problem for several days now and it makes everything more complicated than it needs to be.

If you have any idea of how to solve this problem, please let me know !

Thanks in advance for your answers :)