Payment incorrect after reserving an instance

hi ,buddy , For OpenSearch instances, the fee for m6g.xlarge.search should be halved after reserving m6g.large.search. But in your case, the cost of m6g.xlarge.search remains unchanged. This is most likely due to the following reasons:

1. Reserved instances only apply to the specific reserved instance types, not to larger instance types. That is to say, reserving m6g.large.search instances will only halve the cost of m6g.large.search, not the cost of m6g.xlarge.search.
2. The number of reserved instances you purchased is not enough to cover the number of m6g.xlarge.search instances you used. The discounts of reserved instances only apply to instances that reserved instances can cover. The excess will be billed at on-demand rates.
3. Your OpenSearch cluster may use a mix of on-demand instances and reserved instances. In this case, reserved instances will only discount portions for reserved instances, and the cost of on-demand instances will remain unchanged.
4. The period you purchased the reserved instances does not match the period you are running the m6g.xlarge.search instances. Discounts for reserved instances only apply to the purchased reservation period, and instance costs outside that period are not discounted.
5. Your current billing cycle has not ended yet, meaning you have not started enjoying the benefits of reserved instances. Discounts for reserved instances usually take effect the next billing cycle.