Not sure if its a similar "problem" or not but I have a psd file downloaded from VistaPrint (for their notebook/pad), I edited the file in Photo and added all the textlayers (there was none to start with) - yet when I open it again - they cant be edited. And I have the above checkbox checked.
Is it because Photo cant save as psd? (You have to export it as psd)
I might be missing something somewhere since Im still learning the program mostly by the "learning by doing" way - the text in the help file is so very tiny its quite straining trying to read it and I havent found a way to make that text a little bit bigger).
20 years with PS makes you a bit rusty So SO happy Ive found Affinity tho - and I recommend it to all I talk to (at least one have bought Photo too :))