Mariadb10.6.8 runs out of disk space

I have installed Mariadb-10.6.8 on Amazon Web Service (AWS) RDS instance. The RDS instance has a disk capacity of 150GB and 16GB RAM and it hosts 3 databases of total size 13gb. This database serves a website which hardly has much DML operations and predominately read data from this database using stored procedures. These stored procs extensively use temporary tables and the query performance is well under 1 sec. On the website there would be only around 10 to 25 concurrent users most of the time and at peak time there would be 30 to 35 users. Please note the db engine for all tables are InnoDb

The problem
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When I start the RDS instance the disk space available is 137 GB (with 13 gb used by the data held by the databases). Now as the day progresses and the users access the website the disk space starts reducing drastically and reduces by 35gb in 1 day (though there are hardly couple of inserts/updates). If now I restart the RDS instance then the disk space of 137GB is available again and as the day progresses the disk space keeps on reducing again. So the issue is why is the disk space reducing automatically.