The best solution? Don't use a web browser directly through a smart tv.
For two reasons in the following order:
1) Using a browser on a smart tv allows the potential exposure to malware to possibly damage the software and even the tv set's operating system. Risky business where it's just your tv set direct to the Internet. Without so many hardware and software security protections in comparison used on so many PCs.
2) Not many web developers care much about cross-compliancy beyond the browsers themselves. So online performance through a browser on a smart tv tends to vary greatly for a variety of reasons. With not a lot of incentive for them to improve things at the same level as using a PC to surf the web. (Even Xenforo, the developer of this forum software abandoned supporting such other formats.)
The best best solution? The obvious choice. If you have a smart tv, use its "screen mirroring" function in conjunction with your PC's Windows 10 ability to project your computer screen to your tv set. Where the only role the tv set has is to receive whatever your PC displays. With all the protection afforded you by your PC rather than an anemic and vulnerable smart tv.
Plus you can make the most out of things like ad-blocking and privacy filtering of your browser, so you can skip virtually all commercials associated with various websites like Peacock, Tubi and YouTube offering free high and standard definition movies and television shows. Something that won't happen if you use a browser with a "cast to device" function allowing select websites and browsers to do something similar.
Keep in mind that not all online sources are created equally when it comes to streaming media. Online load and capacity limitations, along with better or worse quality servers are host issues beyond what you the client can control. Having a robust, rock solid Internet connection is no guarantee of a perfect display.
How to accomplish this (at least on a Samsung Smart TV) :
Make sure your smart tv is on and the source is set to "screen mirroring" as opposed to HDMI1, HDMI2, etc. Then on your PC, go to the Windows 10 control panel--> System--> Display.
Scroll down and click on "connect to a wireless display". Look to the right and see if your smart tv is already showing. If so, click the link showing your smart tv's description. Make sure it's your tv and not your neighbors! If it doesn't show, then click the box "Detect" to see if your smart tv name then shows up. Under "multiple displays", be sure to select "duplicate" so the same image on your computer monitor's screen shows up on your tv screen.
If it works, you'll get a little dialog box at the top of your screen that says "Connected to [TV] Sony/Samsung/Etc. From there whatever you display in real time on your computer will show up on your widescreen tv. When you are done watching using screen mirroring, you can click the "Disconnect" function in the dialog box at the top of the screen. Or simply switch your tv's source back to HDMI1 or whatever you had it on previously.
If you have trouble getting it to work, you can always google it as there are many explanations out there on how to do this using various smart tv sets.
This way I can safely watch just about anything I get on my computer and watch it on my tv without any restrictions as there are with "casting a device". Something only certain browsers allow, and can be a real pain to make work.