I had problems with Siptv app on a 4-5 year old Samsung.
Move the cursor to the letter below the icon, the color of the letter will change at this time, click the letter at this time to download and install.
By a process of elimination it came down to the tv software not being able to play some of the current codecs.
I'm so glad to know it's not me and I'm not a total idiot!! I have one filled with menthol that I do not like too much, but it always works great.
And after October 10, all apps of the Saturn, Mars, and Jupiter series will be off the shelf.
Both are very good models.