aws-vault: STS fails due to missing region after upgrade to v6.5.0

After upgrading to v6.5.0 I get the following error when trying to create a session: aws-vault: error: exec: Failed to get credentials for mindhive-ops: operation error STS: GetSessionToken, failed to resolve service endpoint, an AWS region is required, but was not found

I have worked around this by adding the following to my .aws/config:

[default]
region=ap-southeast-2

But that obviously could affect all of my profiles in some way.

Was this intended? That I need to explicitly set a region now?

• I am using the latest release of AWS Vault
• I have provided my .aws/config (redacted if necessary)
• I have provided the debug output using aws-vault --debug (redacted if necessary)

Debug output:

$ aws-vault --debug exec mindhive-ops -- echo hello
2022/02/17 07:54:21 aws-vault v6.5.0
2022/02/17 07:54:21 Loading config file /Users/damon/.aws/config
2022/02/17 07:54:21 Parsing config file /Users/damon/.aws/config
2022/02/17 07:54:21 [keyring] Considering backends: [keychain]
2022/02/17 07:54:21 [keyring] Querying keychain for service="aws-vault", keychain="aws-vault.keychain"
2022/02/17 07:54:21 [keyring] Found 4 results
2022/02/17 07:54:21 profile mindhive-ops: using stored credentials
2022/02/17 07:54:21 profile mindhive-ops: using GetSessionToken
2022/02/17 07:54:21 [keyring] Querying keychain for service="aws-vault", keychain="aws-vault.keychain"
2022/02/17 07:54:21 [keyring] Found 4 results
2022/02/17 07:54:21 [keyring] Querying keychain for service="aws-vault", keychain="aws-vault.keychain"
2022/02/17 07:54:21 [keyring] Found 4 results
2022/02/17 07:54:21 [keyring] Querying keychain for service="aws-vault", account="sts.GetSessionToken,bWluZGhpdmUtb3Bz,,-62135596800", keychain="aws-vault.keychain"
2022/02/17 07:54:21 [keyring] No results found
aws-vault: error: exec: Failed to get credentials for mindhive-ops: operation error STS: GetSessionToken, failed to resolve service endpoint, an AWS region is required, but was not found

.aws/config:

[default]
s3=
    use_accelerate_endpoint = true
    max_concurrent_requests = 15

[profile dev]

[profile mindhive-ops]

[profile *****]
source_profile=mindhive-ops
role_arn=arn:aws:iam::******:role/ops
role_session_name=******
region=us-east-1