I found a work around for the identified issue in Turbo Tax 2018 (desktop).
You can print the individual form by selecting the print icon from the toolbar.
On the next screen, I chose individual forms and then save PDF for your records. This action opens a list of the forms associated with the tax return. I choose the two investment sheets (formerly Schedule 4 and its annex in prior years) and saved them as a PDF.
A work around is a work around... meaning that can we at least know if this issue has been put in the pipeline of bugs to be fixed and will it get fixed in a not too far future? Tks
Carlos in the TT support line researched this for me and was able to determine that the CRA retired Schedule 4 after 2017. The T1 now says "complete the worksheet for the return". Whatever it's called, it should still be included in the pdf and printout. Thanks for the workaround though.