On Ubuntu linux in Bash, credentials are only set after running `assume` twice 

When running `assume my-profile` I get a success message
```
[cf-dev](ap-southeast-2) session credentials will expire 2022-08-04 11:50:47 +0800 AWST
```

However running `env | grep AWS` shows that no credentials are exported into my shell env

Running assume again for the same profile, and repeating the env check shows that credentials are exported.
Then aws commands work as expected