1. The version of Windows you are running (1909) has a limitation which causes performance issues in hardware accelerated applications (such as games and OBS) if multiple monitors with different refresh rates are present. Your system's monitors have 2 different refresh rates (144 and 60), so you are affected by this limitation.
To fix this issue, we recommend updating to at least the Windows 10 May 2020 Update. Follow these instructions
if you're not sure how to update. You should also update per https://obsproject.com/blog/five-simple-tips-for-new-streamers
2. Change the refresh rate on your Dell monitor from 144 Hz to 120 Hz and cap your games at 120 or 240 FPS. Your OBS FPS, refresh rate and game FPS should be multiples of each other.
3. In Windows 10 versions 1809 and newer, we recommend that "Game Mode" be enabled for maximum gaming performance. Game Mode can be enabled via the Windows 10 "Settings" app, under Gaming > Game Mode
4. Display and Game Capture Sources interfere with each other. Never put them in the same scene.
5. Multiple Game Capture sources are usually not needed, and can sometimes interfere with each other. You can use the same Game Capture for all your games! If you change games often, try out the hotkey mode, which lets you press a key to select your active game. If you play games in fullscreen, use 'Capture any fullscreen application' mode.
If still having issues after making those changes then:
1) Restart OBS.
2) Start your stream/recording for about 30 seconds. Make sure you replicate any issues as best you can, which means having any games/apps open and captured, etc.
3) Stop your stream/recording.
4) Select Help > Log Files > Upload Current Log File. Send that link via this troubleshooting tool or whichever support chat you are using.