When you add too many accounts added to a multi user feed it stops showing any tweets.

[Giger22]

When you add about over 22-26 accounts to a multi user feed it does not show any tweets. You have to separate timelines.

26 - https://nitter.net/uefa,cnn,foxnews,cnnbrk,CNNPolitics,ABC,abc_es,CBS,BBC,zeitonline,Gazzetta_it,DiarioAS,elmundoes,swissteam,FlySWISS,Marca,swissinfo,equipedefrance,LeTemps,FuW_News,WSJbusiness,SkyNewsBiz,APBusiness,,SkySportNews,PeterbiltMotors,HISTORY

27 - https://nitter.net/uefa,cnn,foxnews,cnnbrk,CNNPolitics,ABC,abc_es,CBS,BBC,zeitonline,Gazzetta_it,DiarioAS,elmundoes,swissteam,FlySWISS,Marca,swissinfo,equipedefrance,LeTemps,FuW_News,WSJbusiness,SkyNewsBiz,APBusiness,,SkySportNews,PeterbiltMotors,HISTORY,USNHistory

[zedeus]

This has always been the case, see: #83 (comment), #310, and #363 (comment)
An account system will be added in the future that uses a different solution to support "multi feeds" without limits.