Weird issue - schemas missing - on Windows 10 PostgreSQL 14 & 9.6

Hello friends,

I had a Postgres 9.6 server with a few databases running on my Windows 10
laptop. Some months ago I installed version 14 and migrated my databases
across using pg_dumpall and uninstalled 9.6 without deleting the data
folders for 9.6.

I do not use all the databases always, but post upgrade I remember checking
all the databases and they all looked fine. Off late, I was working on a
couple of newer databases and they are all working fine. But now when I
needed to access another older database, I noticed that I can only see the
public schemas in them. In fact all my older databases are only showing
public schema in them. My main schemas just disappeared and they are not
there even in the information_schema if I query the list of schemas.

Honestly I have no idea how and when this happened. The only thing I
remember doing (something perhaps not good) was I entered CTRL+C when I ran
vacuumdb on all databases in version 14.

Now I have one database which is very important for me and my latest
backup, unfirtunately, does not include newer data. So I stand to lose a
few months' worth data if I am unable to restore the schemas back.

I installed 9.6 version again and ran it on another port to see if I can
access the database from the older version. Funnily, that also shows the
schemas missing. This is just not possible as I have positively used the
application that runs off this database some months back.

So all my dear expert admins, is there any way I can restore these missing
schemas in all these databases? I am a bit worried 😞

Please help. Thanks in advance.

Best regards,
Nitin