This is in fact tested by the pandas ExtensionArray tests. However, because pyarrow is an optional dependency, these tests seem to be skipped in the CI here. It can easily be reproduced locally by running the testsuite with pyarrow installed.
I can contribute a fix for this bug, but I don't know the CI here at all (neither GitHub's system, nor how it is being used here), so it would be great if somebody could help adding pyarrow to the CI tests.
This is in fact tested by the pandas ExtensionArray tests. However, because pyarrow is an optional dependency, these tests seem to be skipped in the CI here. It can easily be reproduced locally by running the testsuite with pyarrow installed.
I can contribute a fix for this bug, but I don't know the CI here at all (neither GitHub's system, nor how it is being used here), so it would be great if somebody could help adding pyarrow to the CI tests.