https://us.community.samsung.com/t5/Galaxy-S21/UI8-Android-16-update-SIM-not-recognized/m-p/3415766#M97773 <P>Same issue. After update to OneUI 8 can't connect to network. No access to sim manager. Sim card works on different phone and other sim card doesn't work on my S21FE. Try every advice from Samsung online help and chat. Problem still exist. If Samsung won't fix it in quick period of time I'll stop&nbsp;recommend this brand <span class="lia-unicode-emoji" title=":unamused_face:">😒</span></P><P>&nbsp;</P> Wed, 26 Nov 2025 21:09:11 GMT melon83 2025-11-26T21:09:11Z