SDL is drawing the rectangle in some frames but a weird sliced rectangle in others

Question

I'm trying to draw a basic rectangle using the SDL render API:

#include <SDL2/SDL.h>
#include <iostream>

const int SCREEN_WIDTH = 1280;
const int SCREEN_HEIGHT = 720;

SDL_Window* gWindow = NULL;
SDL_Renderer* gRenderer = NULL;

bool init() {
    bool success = true;
    
    if (SDL_Init(SDL_INIT_VIDEO) < 0) {
        std::cout << "SDL couldn't init! SDL_Error: " << SDL_GetError() << std::endl;
        success = false;
    }
    else {
        gWindow = SDL_CreateWindow("Snake", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_SHOWN);
        if (gWindow == NULL) {
            std::cout << "Window couldn't be created! SDL_Error: " << SDL_GetError() << std::endl;
            success = false;
        }
        else {
            gRenderer = SDL_CreateRenderer(gWindow, -1, SDL_RENDERER_ACCELERATED);
            if (gRenderer == NULL) {
                std::cout << "Renderer couldn't be created! SDL_Error: " << SDL_GetError();
                success = false;
            }
            else {
                SDL_SetRenderDrawColor(gRenderer, 0x00, 0x00, 0x00, 0x00);
            }
        }
    }

    return success;
}

bool loadMedia() {
    bool success = true;
    return success;
}

void close() {
    SDL_DestroyRenderer(gRenderer);
    SDL_DestroyWindow(gWindow);
    gWindow = NULL;
    gRenderer = NULL;

    SDL_Quit();
}

int main(int argc, char* args[]) {
    if (!init()) {
        std::cout << "Failed to init!" << std::endl;
    }
    else {
        SDL_Event e; 
        bool quit = false; 
        
        while(!quit) { 
            while( SDL_PollEvent( &e ) != 0 ){ 
                if( e.type == SDL_QUIT ) quit = true; 
            }

            SDL_SetRenderDrawColor(gRenderer, 0x00, 0x00, 0x00, 0x00);
            SDL_RenderClear(gRenderer); 
                
            SDL_Rect fillRect = {SCREEN_WIDTH / 4, SCREEN_HEIGHT / 4, SCREEN_WIDTH / 2, SCREEN_HEIGHT / 2 };
            SDL_SetRenderDrawColor(gRenderer, 0x00, 0xFF, 0x00, 0xFF);
            SDL_RenderFillRect(gRenderer, &fillRect);

            SDL_RenderPresent(gRenderer);
        }
    }

    close();

    return 0;
}

In some frames SDL will draw the rectangle correctly, but in others the rectangle will draw outside the window and be super stretched with weird slices:

Whenever I drag the window around, it draws the rectangle correctly, but once I stop it will start behaving as I mentioned above.

Honestly, I'm not sure what could be causing it given the code I have.