You might want to make use of a mud cover for unused ports. Aftermarket mud filters also exist, but might be more durable to mount. https://xn--l3ca4bwe5b2b.net/category/%e0%b8%84%e0%b8%a5%e0%b8%b4%e0%b8%9b%e0%b8%ab%e0%b8%a5%e0%b8%b8%e0%b8%94/