Views aggregate queries do not escape the fields that is argument of the aggregation function, nor of the GROUP BY part.
See example below, from Drupal\Tests\views\Kernel\QueryGroupByTest:
SELECT "entity_test"."id" AS "id", "entity_test"."langcode" AS "entity_test_langcode", MIN(entity_test.name) AS "entity_test_name", MIN(entity_test.id) AS "id_1"\n
FROM\n
{entity_test} "entity_test"\n
GROUP BY entity_test.id, entity_test_langcode\n
LIMIT 10 OFFSET 0it is mixing up quoted and non quoted identifiers, now all identifiers should be quoted.
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It's likely this issue predates Contrib.social: some issue and comment data are missing.
Automatically closed - issue fixed for 2 weeks with no activity.
I'm removing credit for #12 since there was already a valid MR here and no need for a re-rolled patch.