Shin splints

You will get a lot of advice and perhaps some misdiagnoses.
To keep it all in perspective assume that the proximate and ultimates causes are only biomechanical. Filter out any advice which does not address your biomechanical issues.
A strong possibility for a major proximate cause is inappropriate shoes. At this point you can get swamped with opinions and diatribes. Essentially, based on years of coaching running to a high level, for elite and for recreational distance and middle distance runners, you should avoid (or minimise) running shoes which are too stiff in every plane of movement; have too much cushioning; a heel to toe rise; flared cushioning around the heels and do not fit your foot shape. This is not about a minimalist v. Heavy shoe debate or even barefoot v. shoes. It is about optimising your foot movement patterns. All of the above features of running shoes contribute to distorting your biomechanical motions. This can lead to much more stress through your shins than should occur in an optimal pattern.

I assume your orthoses are appropriate for running. Often podiatrists have no real idea of the biomechanics of running (somehow a few hours at uni and a complete absence of any knowledge of running training leads mant of them to think they are unquestionable authorities on orthoses that rule every other aspect of running). In every sense orthoses should support not impede correct motion so too podiatrists. If in doubt, shop around.

It is impossible to be sure without seeing you run in your shoes. You have probably now adopted an entire body movement pattern to accommodate poor shoes but it us quite likely that you have imbalances due to weaknesses elsewhere. So even if you start running in optimal shoes you will not quickly adapt your entire body and might even get orher injuries. In other words your entire learnt body biomechanics when running will be an ultimate contributor to shin splints and other potential injuries.

So you need a plan and a strategy if you really want to avoid this injury and others which could be caused by poor running form.

Change your shoes to optimise your own foot biomechanics. Big topic. Go for light thin bendy flat. Get two or more types. Experiment. Change. Cheaper than medical bills.

Change your running biomechanics. Don't do this by following impersonal advice on blogs like this

I've had success with utilizing three pairs of running shoes. I alternate with each run. I had to pay very specific attention to form as well. Because I have disc her nations at different levels, my posture is off. It's awful pain and can be so frustrating to your end goal. Ice ice ice was a great friend while I worked it out.

Haven't had pain for several years now....there's hope.