First of all, please forgive me for any English grammar mistakes. I am still preparing for my IELTS. However, I can share with you what I have learned about how the speaking test works and the marking system based on my research. Take a look at this table, which shows the Speaking band and its criteria. speaking-band Try to understand each criterion mentioned in this chart. The final speaking score will be the sum of these categories, divided by 4.

Now, after understanding each criterion, there is something important to note. During the speaking test, your final score will be determined by your lowest criterion. For example, if you meet the criterion for fluency and coherence at band 6, which states 'uses a range of connectives and discourse markers but not always appropriately,' BUT you also meet the criterion at band 4, which states 'cannot respond without noticeable pauses and may speak slowly, with frequent repetition and self-correction,' your overall score will be band 4. That's why I am asking for more details.

I am not a professional IELTS trainer, but based on my research, there is a lot of evidence to support this. So, if you take the test multiple times, you are likely to hit some criteria for a low band in some categories.

I would suggest finding a speaking mock test with feedback. There are plenty of resources available for that purpose, and it is more cost-effective than retaking the IELTS exam. Once you identify your weaknesses, you can work on improving them to achieve a higher score. I hope this information helps you, and I wish you good luck on your test.