on some cases my salable quantity is greater than my quantity, not for all product but for example to 10 products on 1000. I could not figure out why, I also tried to delete the product and insert it again but the problem persists (it is probably related to the SKU). is there a way to how to decrease salable quantity without placing order?
How to fix the saleable quantity being greater than the quantity.
First take backups of everything just in case you have issues.
Log in to your SSH
Type the following line to list all the inventory mismatches.
A clear list of orders containing the mismatching SKUs will be listed and by how many items they are incorrect on each order.
If you have the following error see resolution below:
In Abstract.php line 144: SQLSTATE[HY000]  Connection refused
In Abstract.php line 128: SQLSTATE[HY000]  Connection Refused
Resolution to above error: Open your FTP software and log on to your server. Navigate to /app/etc Download the env.php file Edit the file to change the following line: 'host' => 'localhost', Change it to this: 'host' => '127.0.0.1', Upload the file back to the server to replace the existing env.php
Then type the following line:
bin/magento inventory:reservation:list-inconsistencies -r | bin/magento inventory:reservation:create-compensations
This may take several minutes but eventually you will be presented with a list of the compensations created which will correct your stock quantity for each of the items which were incorrect.
The original problem for me happened when I was correcting old orders and setting them to shipped/dispatched and also creating credit memos for refunded or cancelled orders.