I don’t own a treadmill but I have worked with belt conveyors!

My first guess would be belt tension.

It looks as if there are YouTube videos which show how to tension treadmills.

My only real advice is to make sure you pull the roller back evenly, otherwise you may get tracking issues (the belt wanders left or right).

Do you think it would it work with dry products, including salt?

If so, that is a large percentage of packaging which this material can replace.

As long as the UK one is blue.

I hear what you are saying, but I’m not sure why you aren’t doing what you want to do.

If you have a computer not provided by work, why do you have Slack or Teams?

Use ad blockers and/or Pi-Hole to avoid pesky ads.

Watch live TV.

Write a letter.

Stay away or use sparingly, data hungry services.

I know I feel better for it and I don’t feel as if I’m missing much.