9.5.3: substring: regex greedy operator not picking up chars as expected

Hello,

For the following query:

select substring('>772' from '.*?[0-9]+')

I would expect the output to be '>772', but it is '>7'. You can also see the expected result on https://regex101.com/, although I am aware not all regex processors work the same.

The following queries:

select substring('>772' from '^.*?[0-9]+$')

and:

select substring('>772' from '[0-9]+')

both return '>772', which is expected. Could the less greedy operator on the left (.*?) be affecting the more greedy right one (+)?

Thanks,
Russell Foster