Dear Alejandro
I see in the Technote you provided that you can use *SYSTEM DCM store as well. So, no issue in this point if you already created a self-signed (Local) certificate in DCM.
After you applied the latest HTTP group PTF, did you check its application status with WRKPTFGRP to make sure it is applied fine? Also did you try restarting HTTP Admin server yet?
If you did both already, based on the fact that all Navigator for i functions are coded in JAVA, I suspect you need to apply latest group PTF for JAVA as well according to this statement "The Navigator for i PTFs are shipped in the HTTP group. It is recommended that you use the latest group PTF and also keep current on related PTF groups listed here:" which is from this Technote: IBM Navigator for i - PTF Information at https://www.ibm.com/support/pages/node/6486565
Before applying JAVA group PTF, I suggest you use this JDK in your IBM i : 64-bit Java™ 17 - 5770JV1 option 20 and also set the proper JAVA_HOME env var to ADDENVVAR ENVVAR(JAVA_HOME) VALUE('/QOpenSys/QIBM/ProdData/JavaVM/jdk17/64bit') LEVEL(*SYS) (then check with WRKENVVAR) and then apply its latest JAVA group PTF.
Navigator for i also needs this component: Java Toolbox & Extended Base Directory Support - 5770-SS1 option 3.
------------------------------
Satid S
------------------------------