The slowness makes the drone operate slow when switching modes, recording, etc.

Hello and good day AntDX316. Thank you for reaching out and thank you for the information you have shared with us. Just a friendly reminder I would suggest using or buying an SD card that is recommended by DJI for your DJI Drones. These recommended SD Cards are test by our DJI engineers to work properly with the said drone. Thank you for your valued support.

DJI Stephen Posted at 6-21 08:34
Hello and good day AntDX316. Thank you for reaching out and thank you for the information you have shared with us. Just a friendly reminder I would suggest using or buying an SD card that is recommended by DJI for your DJI Drones. These recommended SD Cards are test by our DJI engineers to work properly with the said drone. Thank you for your valued support.

The V30 is recommended.  My Phantom 4 Pro V2.0 operates as smoothly as the Mavic 2 Zoom with the V30.

Thank you for the additional information you have shared AntDX316. Have a safe and happy flying always.

I use the SanDisk Extreme Pro V30, A2, U3

Same here