Don't waste your money for re-eval. Just use the extra money somewhere else. This has a validity of 2 years only. If you badly need a high score now, prepare 3 months and re-take it again. Or wait 1 year.. this will extend validity

mine is expiring and I still don't have PR so I might need to re-take again in December. Speaking is your lowest skill but this is subjective and depends on whoever is the interviewer. First time, I had 7.5 in speaking and then I took again, I had 8.5. I don't think I did something different with the latest speaking result from my previous attempt. The only difference was the interviewer. Congrats on your band 7. That's always hard to achieve.
PS I paid for reval from my previous ielts and believe me, I regret wasting that money.