problem Hz

Hi everyone, I have a problem, when I start Kodi, the TV changes the refresh rate to 60Hz. in the video control panel it is set to 50Hz, but every time I start Kodi it switches to 60Hz, when I close Kodi the TV returns to 50Hz. If you’re interested, my audio/video chain is PC-video card (RX560), HDMI, amplifier, HDMI plasma TV. with kodi 18 and 19 I never had this problem. Thanks everyone, have a good evening.