Cannot find ID , but really exists in Postgres - sql

Question

I am trying to pull data from a database to create a progress board fro some this query keeps returning for output."Data", even for values of projectId that actually exist in DB, project_id is an id that is inputted into the function.
-- FUNCTION: "ProjectProgress"."GetStepStatusbyProject"("Common"."InputDBMessage")
-- DROP FUNCTION "ProjectProgress"."GetStepStatusbyProject"("Common"."InputDBMessage");
CREATE OR REPLACE FUNCTION "ProjectProgress"."GetStepStatusbyProject"(
userinput "Common"."InputDBMessage")
RETURNS "Common"."OutputDBMessage"
LANGUAGE "plpgsql"
COST 100
VOLATILE
AS $BODY$
-- History:
-- 04/24/2020 Nick: Created Function
DECLARE
status_info jsonb;
input_params jsonb;
project_id bigint;
project_exists bool = true;
output "Common"."OutputDBMessage";
BEGIN
input_params := userinput."Parameters";
project_id := input_params ->> 'Id';
PERFORM "Log"."LogBeginRoutine"(userinput."UserName", userinput."ApplicationName", 'StepStatuses', 'GetStepStatusbyProject', userinput."ClientId", userinput."SessionId");
SELECT INTO project_exists (EXISTS(SELECT * FROM "LIMS"."Projects" WHERE "Id" = project_id));
IF NOT project_exists THEN
output."ErrorCode" = 1;
output."UserMessage" = 'project_id id not found';
ELSE
SELECT
array_to_json(array_agg(( ss.*, st."Color",st."Description",st."Icon"))) INTO status_info
FROM "LIMS"."Projects" as pr INNER JOIN "ProjectProgress"."Steps" as s
ON s."ProjectId" = pr."Id"
INNER JOIN (
SELECT
stepstatus.*
FROM
"ProjectProgress"."StepStatuses" AS stepstatus INNER JOIN
(
SELECT
MAX("Id") m_id, "StepId"
FROM
"ProjectProgress"."StepStatuses"
GROUP BY "StepId"
) AS mss ON mss.m_id = stepstatus."Id"
) as ss
ON ss."StepId" = s."Id"
INNER JOIN "ProjectProgress"."StatusTemplates" as st
ON ss."StatusTemplateId" = st."Id"
WHERE
st."Description" != 'Not Started' AND pr."Id" = project_id;
output."Data" := status_info;
output."ErrorCode" := 0;
output."UserMessage" := 'status successfully retrieved.';
PERFORM "Log"."LogEndSuccessRoutine"(userinput."UserName", userinput."ApplicationName", 'StepStatuses', 'GetStepStatusbyProject', userinput."ClientId", userinput."SessionId");
return output;
END
$BODY$;