Problems with saving to external hard drive?

I'm currently in training. In the vocational school we usually have block lessons. And we work with laptops in the classroom where we have to work with laptops, but we do not get asked. That's why I got a second device with only Word, Excel and Powerpoint on it.

But since I'm 40 km from my facility (and school - the vocational school is located directly on the site of the hospital), I take only the external disk home with my folder. Everything else I lock in my spint at school.

Now I have often found that the files I have stored on the hard drive via the PC at school are gone when I look at the hard drive at home. I have definitely saved it.

It can't be different versions of the software, because I have the same operating system and the same version of Word and Excel on both laptops. In addition, the saved file is completely gone. I've saved it for sure because I worked on it for several days in a row at school.

I did not save them on the laptop at school either. And even if I plug the external hard drive back into my laptop at school, the file will disappear.

what am I doing wrong?

Have you properly "removed" or simply agreed / taken out?

Yes, I have removed it properly. But that was probably the mistake. Most of the data was then gone when I told the och, he should remove the stick before I pulled it out of the device.