updateOne matches but doesn't update

Working with Data
, ,
2

Just to note, changing the query as follows:

updateOne(
   { userId: "100", guilds: { $elemMatch: { guildId: { $eq: '1' } } } },
       { 
          $set: { 
             "guilds.$.xp": 5,
              },
       },
 );

Does update the database, however it deletes the array and replaces it with an empty Object named guilds