Setting spring.jpa.open-in-view=false makes API responses inconsistent, giving 500 error to client - spring-boot

Question

Since I started working on a spring-boot application, I use to see the following warning during service startup
2022-09-20 17:59:49.061 WARN 10776 --- [ main] aWebConfiguration$JpaWebMvcConfiguration : spring.jpa.open-in-view is enabled by default. Therefore, database queries may be performed during view rendering. Explicitly configure spring.jpa.open-in-view to disable this warning
To address this, I recently added the spring.jpa.open-in-view=false in application.properties file to disable this warning and it worked.
However, after doing so, some of the endpoints became inconsistent in sending the response! For instance:
User-1 requesting an endpoint gets HTTP/1.1 200 response w/ JSON body
User-2 requesting the same endpoint gets HTTP/1.1 500 response w/o any body
Ideally, both the requests should fetch a JSON response body having list of Objects (different objects based on user)
In chrome's network tab, I see the following response for User-2
HTTP/1.1 500
Content-Type: text/html;charset=utf-8
Content-Language: en
Content-Length: 820
Date: Tue, 20 Sep 2022 12:43:55 GMT
Connection: close
There are no warnings, errors, exceptions of any sorts logged in the server log. From the start of the function execution till the returning of response, all the logs seen are expected ones.
The same User-2 making the same request when spring.jpa.open-in-view=true will fetch the following response (and 5 Objects in the list).
HTTP/1.1 200
Vary: Origin
Vary: Access-Control-Request-Method
Vary: Access-Control-Request-Headers
Access-Control-Allow-Origin: *
X-Content-Type-Options: nosniff
X-XSS-Protection: 1; mode=block
Cache-Control: no-cache, no-store, max-age=0, must-revalidate
Pragma: no-cache
Expires: 0
Strict-Transport-Security: max-age=31536000 ; includeSubDomains
X-Frame-Options: DENY
Content-Type: application/json;charset=UTF-8
Transfer-Encoding: chunked
Date: Tue, 20 Sep 2022 12:52:04 GMT
Is there any related configuration that needs to be done along with spring.jpa.open-in-view=false setting?
Also, should I really need to worry on changing the default value? How will this setting impact the application?
My environment info:
Java: 1.8
MySQL: 5.7
Spring-Boot: 2.1.2.RELEASE
Spring Tool Suite: 3.9.9.RELEASE
All the queries are in #Query annotation in extended JpaRepository interfaces.
application.properties:
logging.level.org.springframework.web = INFO
logging.level.org.hibernate = INFO
logging.level.my.packages = TRACE
spring.jpa.hibernate.naming.physical-strategy = org.hibernate.boot.model.naming.PhysicalNamingStrategyStandardImpl
spring.jpa.properties.hibernate.dialect = org.hibernate.dialect.MySQL5InnoDBDialect
spring.datasource.url = jdbc:mysql://localhost:3306/dbname
spring.datasource.username = username
spring.datasource.password = password
I'm trying to understand the reason behind this unexpected behavior. Any info could be helpful.
Thanks