This is usually the result of excessive repetitive forces during standing and walking.
Have you addressed your feet or ankle at all?
Some tighness etc in these areas can increase the force that the peroneal tendons are exposed to.
This situation needs to be resolved for the tissues to heal.
What is your foot position when walking or standing?
What are the sliding surfaces like in this area?
Have you voodoo flossed your ankle at all?