Feeling isolated

Hi all,
Been at a workplace for a year in Hertfordshire. Like the people and the job but feeling upset at the moment. I was given a tour of another centre to work in - only to be told that I will be working there by the manager at the site. My own manager didn't even tell me other than hint that I would occasionally shadow there. Three other coworkers from other sites were meant to join me for this 'tour' but mysteriously pulled out last minute. The managers at this branch looked a
bit sorry for me and one said they were waiting on a decision from a third party. My manager at my branch asked me for my feedback about how the visit went. I've not fallen out with any coworkers in the team I work in including my boss and have chatted, bantered and worked hard to put events together and work in a small team. Added to the mix, I have a male coworker from another department of a government organisation I work with that either flirts with me or refuses to cooperate on business matters and gives me daggers when he walks past whilst schmoozing with my manager and flirting with my other colleague. I do not expect to be friends with those I work with but I am feeling upset about being left in the dark about a potential move to another site whilst working with a man who either tries to show off in front of me or refuses to follow through with business transactions. I asked him to promote an event I was hosting - only to find my leaflets back on the reception desk. Any advice because I just want to get on with my job and everyone. Many thanks.