DDB Q&I performance critical - 5,000 - 9,000 ms

I can't believe the DDB itself is 238TB in size, so I expect this to be the footprint of written data towards Azure Blob Storage that is related to the DDB. Is it a single MA with one DDB? Which version are you running?

The problem in Azure was always that there wasn't a decent low latency storage offering available and you have to create a stripe set spanning multiple disks to get more IOps, but still latency sucked and was not very consistent. Nowadays you can pick Premium SSD v2 or go for Ultra Disk, but before moving towards a different storage offering please make sure your DDB is optimized to have the latest enhancement enabled such as garbage collection and that it doesn't contain a lot of white space as this also impacts performance. The documentation contains a lot of information, but you can always consider opening a ticket and have someone from support to perform a quick assessments.