when grouping by tags, tags with different casing will be grouped together

app/src/main/java/eu/kanade/tachiyomi/ui/library/LibraryPresenter.kt

@@ -25,6 +25,7 @@ import eu.kanade.tachiyomi.ui.library.filter.FilterBottomSheet
 import eu.kanade.tachiyomi.ui.library.filter.FilterBottomSheet.Companion.STATE_EXCLUDE
 import eu.kanade.tachiyomi.ui.library.filter.FilterBottomSheet.Companion.STATE_IGNORE
 import eu.kanade.tachiyomi.ui.library.filter.FilterBottomSheet.Companion.STATE_INCLUDE
+import eu.kanade.tachiyomi.util.lang.capitalizeWords
 import eu.kanade.tachiyomi.util.lang.removeArticles
 import eu.kanade.tachiyomi.util.system.executeOnIO
 import kotlinx.coroutines.CoroutineScope
@@ -536,7 +537,7 @@ class LibraryPresenter(
                         listOf("Unknown")
                     } else {
                         manga.genre?.split(",")?.mapNotNull {
-                            val tag = it.trim()
+                            val tag = it.trim().capitalizeWords()
                             if (tag.isBlank()) null else tag
                         } ?: listOf("Unknown")
                     }

app/src/main/java/eu/kanade/tachiyomi/util/lang/StringExtensions.kt

@@ -35,6 +35,11 @@ fun String.truncateCenter(count: Int, replacement: String = "..."): String {
     return "${take(pieceLength)}$replacement${takeLast(pieceLength)}"
 }
 
+fun String.capitalizeWords(): String {
+    val firstReplace = split(" ").joinToString(" ") { it.capitalize() }
+    return firstReplace.split("-").joinToString("-") { it.capitalize() }
+}
+
 /**
  * Case-insensitive natural comparator for strings.
  */