Can we clarify that the bone was the fibula, not the tibia (I suspect as much since you seem to be doing well fairly soon after. The tibia is the main bone of the lower leg (ie the shin bone) whereas the fibula is the bone on the outside of the lower leg. Important to know as the tibia is the main weightbearing bone of the lower leg, the fibula not so much (it's main purpose is for muscle attachments and to help form the ankle joint.

Generally you will return to sport MUCH quicker with a fibula fracture, which is why I suspect this is what you are referring to.

As for the clinical side of things...
Can I ask why you are getting an ankle support? Just because it feels weaker since the plaster? If so, I would caution against relying on a brace rather than engaging in a comprehensive rehab program. But if it is just to protect it until you get that ankle stronger, then it's probably ok.

You say the ankle moves well - is it the same as the other side? Lay on the floor with feet side-by-side to compare the following movements: 1. point toes down, 2. pull toes up, 3. turning soles in to face each other, 4. turning soles out away from each other. Look closely for any difference in range.

If they aren't equal, make correcting this your priority. If they are equal, focus on proprioception and strength - post if the range of motion is equal to the other side and we can post some proprioception/strength suggestions.