"Cross Origin Request Blocked" No solutions seem to work - node.js

Question

Background
I'm building a MERN full stack application as a personal project. I am running the frontend client on localhost:3000 and the server on localhost:5000.
Problem
All of my API routes work as expected except for a GET request, router.get('/get-friends', ...) which queries the mongoDB to return a list of collection documents. Calling that get request on Postman returns the expected output. I decided to write a simple GET request that returns a method and it works just fine in my browser
When making the request the get-friends request in my browser, I get the following log:
Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at http://localhost:5000/api/users/get-friends/. (Reason: CORS request did not succeed)
What I've Already Tried
Enabling cors in my Express server
Enabling cors preflight
Adding a proxy to the server from the client's package.json
Switching from Axios to vanilla JS's fetch() method
Turning off cors in my browser
I suspect the issue occurs when I make the request to the database from Express. I am really not sure how to solve this issue.
Here is the route in question:
router.get('/get-friends', (req, res) =>{
var species_ = req.body.species;
var gender_ = req.body.gender;
var neutered_ = req.body.neutered;
// query db
Friend.find({species: species_},{gender:gender_},{neutered:neutered_}).then((friends_) =>{
if(!friends_){
return res.status(404).send('query error, nothing returned');
}
return res.send(friends_);
}).catch((e) =>{
res.status(400).send(4);
})
});
Here is the project repo and the relevant files are:
https://github.com/edgarvi/foster-friends/server.js (Express server)
https://github.com/EdgarVi/foster-friends/blob/master/routes/api/users.js (Routes for the express server)
https://github.com/EdgarVi/foster-friends/blob/master/client/src/components/layout/SearchFriends.js (React component which calls the server)
I would gladly appreciate any help!

Answer 1

I have highlighted possible problems.
Reason: CORS request did not succeed
The HTTP request which makes use of CORS failed because the HTTP
connection failed at either the network or protocol level. The error
is not directly related to CORS, but is a fundamental network error of
some kind.
> In many cases, it is caused by a browser plugin (e.g. an ad blocker or
privacy protector) blocking the request.
Other possible causes include:
Trying to access an https resource that has an invalid certificate
will cause this error.
Trying to access an http resource from a page with an https origin
will also cause this error.
As of Firefox 68, https pages are not permitted to access
http://localhost, although this may be changed by Bug 1488740.
> The server did not respond to the actual request (even if it responded
to the Preflight request). One scenario might be an HTTP service being
developed that panicked without returning any data.
https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS/Errors/CORSDidNotSucceed

Answer 2

Thank you all for the help and the suggestions. After struggling through this for multiple days, I finally encountered a solution.
In my react client, I made the API call:
axios.get('http://localhost:5000/api/users/get-friends',
{
params: {
species: this.state.species,
gender: this.state.gender,
neutured: neutered_
}}
);
and then I changed the Mongoose query to look like:
router.get('/get-friends', (req, res) =>{
var species_ = req.query.species;
var gender_ = req.query.gender;
var neutered_ = req.query.neutered;
// query db
Friend.find({species: species_},{gender:gender_},{neutered:neutered_}).then((_friends) => {
return res.send(_friends);
})
});
I'm not exactly sure why these changes made my code finally work but once again, thank you all for the help and suggestions!