It sounds like you need to start with glute activation exercises. But there could be more that needs attention as you progress through that path.
You said you were diagnosed – I assume by a medical professional? Did they recommend a corrective course of action? (maybe you don’t agree with it?) They could refer you to a PT so that you can specifically isolate the dysfunction and begin work to fix it.
The problem with the human bodie’s complexity. If there’s an issue, it’s likely a fault in multiple systems. In this case, the glute issue is a system already identified. But why did is this system nor working properly? A common answer is because it had to compensate for another system not working properly. So that system will need to be addressed as well – otherwise the glute issue will just come back along with your FAGS(wow, what a horrid acronym).
So if you want to address the issue efficiently – seek a trained individual. If you’d like to try and fix it on your own and that’s why you’re here – then the simple logical response to your question is the glute activation work such as bridges, cook lifts, etc.
From the mobility side of things – the basic approach is to look upstream and downstream of your issue. Work the lumbar and T-spines, Hip, and upper leg/knee area. Check out the video section under “Episodes” for all types of goodies. See what makes you feel like you’re waking things up and finding weakness and work in those areas an efficient manner. *It takes 2 minutes of mobility work to instill permanent change in soft tissue*