DriftyGames - any chance you can confirm the following, it looks like it's the case and I used both the clean install and the walkthrough mod to test.
I've seen it mentioned in here before & don't know if the wishing Lexi "Good luck" bug (via Nuke whilst shopping with Linda/Cece) has been fixed but it looks like the net result is that the variable "ep2LexiReply" is not being set to "True" anywhere - and at the end of the chapter it states that you didn't manage to give Lexi your phone number.
If you want to successfully give Lexi your phone number (to presumably enable further progression with her) you can do it via the console.
(1) First you'll have to edit the "console.rpy" file in <path to game>\renpy\common with something like Notepad++ and change "config.console = False" to "config.console = True"
(2) When shopping with Linda/Cece and the MC & Chris are sat down you see the comment "If only I had something to do right now." Open Nuke on the phone, respond to the photo of Lexi from Chris and you get stuck on "Good Luck"
(3) Exit the phone and when Chris falls backwards to sleep you see him "zzz". Press <Shift>+o to access the console and enter:
$ ep2LexiReply = True
(4) Hit <Esc> to exit the console and after the MC says "I envy you, Chris..." you should be able to go back to the Nuke app on the phone and find that Lexi has responded to the photo of the MC in a towel & rabbit slippers. If you didn't change the "ep2LexiReply" variable there won't be a response.
At the end of the chapter you should then see that you were able to give Lexi your phone number.
The only file containing "ep2LexiReply" is "script02.rpy" (for chapter 2) and it's in 2 "if ep2LexiReply:" statements - for the reply about slippers from Lexi above and for confirmation that you gave her your number at the end.