Question 4:3 stretched CSGO

[GuiLLeBu]

When i open CSGO on 4:3 stretched works fine, but when i press the widows key and then return to CSGO the black bars appears, and have to restart the game in order to have 4:3 stretched again. Any suggestions to fix it? My graphics card is an RX 570 4gb

 

[eibelbilly]

Go in the game settings and try 16 by 9