According to the League of Legends server status page, Patch 8.6 will be applied on March 22, a day late.
Though patches are typically applied on Wednesday mornings, this one will be rolling out later due to some issues found as the patch rolled out in Oceanic and Japanese game servers.
Those two servers have already received the patch update, which is how these issues were found. Because of the mismatched patches, server transfers for accounts will also be temporarily disabled until every region is on 8.6, according to this forum post.
There’s no specific details as to what the found issues in Patch 8.6 were, but you’ll be able to play on the new patch soon enough! For now, you can get caught up on all the changes here and check out the most important parts of the patch here.
This article will be updated as more information becomes available.