Making sure you are moving the infusion area and try to find "new" territory. Keep track if it happens in a certain area more than others. Sometimes changing the type of infusion sets works. Steel sets etc. Switching the depth or the material that's used. Unfortunately it's not uncommon to have site problems. I don't use a tubed pump but I have been having more and more trouble with my pod pump. In my case I can't change my infusion set because pods don't differ. But I have been having to change my pod out more every 2 days, my site really likes to fail the end of the second day.You can talk to your diabetic team to see what other choices you have for infusion sets if needed? Sometimes making sure the site is really secure helps so tunneling doesn't happen as easily. Giving smaller doses in increments at a time can also help instead of one larger bolus.
If it's been going on for a few months I doubt these next are the problem. But there are some other things that can cause issues. Hidden infections like a tooth, some medications can cause it too, steroids are notorious for it. Also hormones can always change and can cause an issue when it's that time of the month and the week before can cause issues for some.
I hope you figure it out!