videos do not play consecutively

When I try to mail videos to family or when I play them myself some play normally that is if there are 12 vides they will just keep right on playing 1234 without stopping and having to start the second one then the third, then the 4th.
I have tried ripping with VLC. I have tried using Gmail clicking on compose then attachment then recipients. I have also tried. Using just the contents of the videos. To send. for the most part. The video will play and stop or loop. And then I have to click on the second video but it to do the same thing. Every once in awhile I will play a video and it will go 1234 without stopping as they should. Have you have any idea what could be causing this. Is it the way I took them one video then stopping and taking the second and then burning the DVD. Or is it the way I'm sending them to people? I have used WMP, VLC, Gmail etc.
The one thing in commons each video on a disc playing and stopping until play the second manually. That's the problem.
I have used different cameras over the years. I have burned hen different ways. I have uploaded them ripping first then sending as attachment then others I have in the cloud for family to see.
I consider myself lucky when a series of video as on a disc play continuously with no break but don't know how to do that consistently.
Thank you.

I haven't done it in several years but if one has access to a Mac computer with its QuickTime it might be possible to do as desired. A caveat would be how large the resultant file would be and putting it where someone could download it. Unfortunately QT for Windows was discontinued.

I am using Windows and their Video Editor seems to do the job converting videos to MP4.
Hand Brake is the most used to illegally by pass patents which I don't do. It does not have to do just that but I am going for simplicity.
not needing codecs or special files.
My whole family went with Apple except me. I have the iPhone13 which is nice. I should have started with Mac with everything.
Thankyou for the reply

You're welcome. I used to have a MacBook Pro from mid-2010 with Mac OS X but there was a failure on the motherboard just as the new macOS came out, haven't come up with extra money to get a new one.

I understand it is hard to suit your digital equipment till your wallet everything is so expensive.