Yep! the wrong bobbin can give you all kinds of trouble.

Except for my featherweight, I have used either plastic or metal in my machines, several vintage singers and a walmart version of a Brother and haven't had any issues yet.

most machines have specific bobbins- i use the ones made for the machine

I always use the bobbins suggested in the manual for the machines

My Singer is about 15 years old. I have tried all kinds of Singer bobbins and could not find one that would work. I can tell because only the correct bobbin works on the bobbin winder. After reading this board for a while, I learned there are different Singer bobbins. My manual did not tell me. I had to go to the tech info for my model on the Singer web site to find that I needed a 15J. They are hard to find. I finally found some at a sewing machine parts site. And they only come in plastic.

Find out the correct bobbin for your machine. I saves a lot of problems. It is not true that a bobbin is a bobbin is a bobbin.

My Pfaff came with a metal bobbin, and it also uses the plastic ones. I use both and don't find much difference on my machine. The metal ones hold more thread than the plastic ones.

yes, it makes a difference..IMHO..i use only janome bobbins in my machine..they may look the same as the class 15 plastic bobbin, but if you close your eyes and feel them..you will feel that one is a little rounded on the sides, and the other is not.

Ditto. I have both, depending on the machine,

I have a Quantum Futura - it come with a plastic bobbin - so I bought more Singer bobbins - not all plastic bobbins fit the same! It ruined my bobbin carriage and had to replace it - it had to be a bobbin made exactly for the Quantum Futura! The repair person showed me the ever so slight difference in the way the bobbin was made! So, as Barb 44 just stated, it is not true that a bobbin is a bobbin is a bobbin!!!! From experience I found out!

I use prewound embroidery paper bobbins that I buy a 1000 in a box.