The phrase "although it was supposed" is correct and usable in written English.
It can be used to introduce a contrast or contradiction regarding expectations or intentions.
Example: "Although it was supposed to be a simple task, it turned out to be quite complicated."
Alternatives: "even though it was meant" or "despite being intended".
"Although it was supposed to only be for 2014, Stefan was great and agreed to extend the partnership through this year which I really appreciated.
In the Holy of Holies of the Jewish Temple in Jerusalem there was no picture of Yahweh in or on the ark of the Covenant, although it was supposed to be a sort of portable throne for God.
And although it was supposed to protect JPMorgan Chase's business dealings in China, the program went so off track that it is now the focus of a federal bribery investigation in the United States.
However, although it was supposed to be available to the rest of the UK on STV Player, millions were denied to opportunity to watch when the live stream failed across the rest of the UK.
"Come to the revolting restaurant," read the huge sign at Calgary airport, and although it was supposed to say "revolving", that burnt-out section of neon tube did not lie.
And although it was supposed to protect JPMorgan Chase's business dealings in China, the program went so off track that it is now the focus of a federal bribery investigation in the United States, interviews and a confidential government document show.
Although it is supposed to be rigorously monitored to prevent people buying prescription drugs, reports indicate that these are routinely circumvented.
Although it is supposed to remain fixed for 12 months at a time, the price can be adjusted if energy markets spike up or down.
Although it is supposed to be illegal to pay staff below those levels, employers are using a variety of ruses to sidestep the rates.
Under that agreement, the United States is not required to hand over criminal suspects until they are formally charged, although it is supposed to "consider" requests for custody before indictment.
Although it's supposed to be breezy comedy (check out that titular exclamation mark!) in the mould of, say, Catch Me If You Can, it's even more boring on screen than it sounds on the page.
