I have Samsung Notec20 Ultra. Since July my sms and mms and whatsapp option to send any size video is not working. the video loads and then doesn't send generating an error message unable to send video due to exceeding the size limit. Samsung and Tmobile tech support unable to figuere out solution.
First of SMS/MMS allows you to send files with a limit of around 2-5MB, and 100MB if you have RCS or Advanced messages (depending on the messaging app) working. WhatsApp, recently, allows for a maximum of 2GB worth of files to be sent at once. So anything exceeding that limit in the respective app will encounter that error. But since you said "any size video" then make sure that you don't have data restriction enabled on your phone. Also try seeing if you can lower the video quality before sending.
Camera App>Settings>Advanced video options. Toggle off High efficiency videos and HDR10+ videos.
