1. Restart your device A simple restart can often resolve software glitches and clear temporary errors
2. Check for software updates It might be a software glitch associated with a recent update, check for a newer update which might contain the bug fixes to this and install
3. If none of the above solutions work, contact samsung customer support, they'll give you expert assistance, here is their chat link so you can chat with an expert, they work between 8am & 8pm, so that's when you are able to chat with them https://www.samsung.com/africa_en/support/?cid=sea-alert-redir
If restart fails check if there isn't anything stuck in your charging port, possibly debris or something. When your phone displays "OTG connection," it means it's detecting a USB On-The-Go connection or something.
