I know you said you solved this, but I still wanted to clarify some things. Gnome Terminal sort of muddies the term “Profile” by storing both appearance and configuration settings in profiles — the appearance settings can be activated in existing terminals at any time, using “Terminal > Change Profile > [selection]” in the menu. The configuration settings, things like “Run a custom command instead of my login shell”, are only applicable when creating a new terminal.
In other words, if you have a “Run a custom command…” profile that you want to use, you can’t create a default-profile tab/window and then Change Profile to the one you want. You can activate it with “File > New Tab (or Window) > [selection]”. But if you “Change Settings” to the new profile, it’ll just ignore the different configuration, and only apply any differences in appearance.
I keep Profile definitions around for logins to each of the other hosts on my local net, with “ssh hostname.local” set for the “Run a custom command…” preference on each. When I want to open a session on one of those hosts, I use “File > New Tab > [host profile]” to open one. (Then, #PROTIP, I can use Ctrl+Shift+T in one of those tabs, to create an additional session using the remote profile. Ctrl+Shift+T will create a new tab using the same profile as whatever tab you’re currently in.)
But “Change Profile”, if that’s what you were using, isn’t really meant for switching between profiles that use custom commands. (In fact, my personal opinion is that “Change Profile” is utterly worthless.)