"Out of capacity" in Japan East (Tokyo) region

Summary

"Out of capacity" when creating Compute Instance for shape VM.Standard.A1.Flex in Japan East (Tokyo) region

Content

 I have been trying to create a compute instance using shape VM.Standard.A1.Flex for over a week now but have not been able to create it successfully. The error I get is: Out of capacity for shape VM.Standard.A1.Flex in availability domain SGAf:AP-TOKYO-1-AD-1. Please try again later.

Initially, I configured to use 4 OCPU and 24 GB memory but got the above error. Then I tried reducing it to 1 OCPU and 6 GB memory (as default) but the above error still occurs. However, I can still create compute instance using VM.Standard.E2.1.Micro shape without any errors (but I need VM.Standard.A1.Flex).