Lag only in the nether

Hello i have rollback and lag only in the nether (realms/bedrock/No mod add) not in the basic world. Sometimes when i destroy bloc or when i hit monster the action is performed only 3-5 second later, and this happen like every 20-30 seconde, at the first time in the nether it was fine but since a few days it lag reccurently. i have search on the web but don’t find similar problem with solution. (sorry for my english i’m french) have a beautifull day !