I do not know exactly what's going on with your particular situation, but I would approach the problem the following way. Apologies if you are already aware of this approach & have tried it. Maybe it'll help someone else.
-In the "home" tab, look in the "data" grouping
-Click on "points" button (A)
-That opens a project tab named "points spreadsheet" (B)
-Click the top of the feature code column. This filters your points by feature code (C)
-Click the arrow next to your furthest left column (point ID) (D)
-Cntl click to include all the points you want. This will select all of them. (D)
-You can click on the "Plan View" tab to get back to your project & see that they are all selected. (E)
This won't work if you had some codes with 23 in the middle. Only for the codes that begin with 23, or EP, etc...
Hope this helps.