download failures

I'm on an older Mac, using 10.6.8, highest version I can upgrade to.

I've been using WeTransfer and MediaFire for years with no issues (a few connection issues but that would happen no matter what service I use). Lately, downloads are failing from both these services when they hit about 90% downloaded. The download just freezes and after a very long time, fails. These area always on long downloads - right now it's failing on 2 different files, one from WeTransfer and one from MediaFire, both of which are over 100MB. Smaller downloads are succeeding.

Something must have happened recently to cause these failures. I've pulled 1GB files from these sources before without issue but the last month I can't get anything.

I'm running a small business and need to get this issue solved or I've got major problems. Can someone offer a suggestion on how to get my downloads going again please?