I dont really know Symbicort - but are there different stregngths? Can your pulm increase strength of med or try a diff one ? Few years ago i was on medium strength advair discus, then for short time, doctor put me on next one up because of flares up, then we changed advair hfa , these are puffs, i am on 230/21 which is highest strength 2puffs am and pm as baseeline drug. But when i feel ok, md lets me cut down to one puff in pm and if still ok to one puff in am. Though, when my breathing is off, i also have spiriva, it helps with small airways per md. In your case @britelite , If its been fews months of wheezing - something doesnt add up. No matter if its long covid or what not, your symptoms are not managed, from what i read. When was the last time you seen your pulm md? Pulm mds are pretty good at managing symptoms and/or rule in/out where wheezing comes from. If same pulm says "long covid", consider 2nd or 3 rd opinion.
They will /can redo lungs function tests (there are few diff kinds), 6 min walk test, etc.

Also has your pulm md tried (a steroids burst ) to help with wheezing and cough or put on abx short term or for maintenance.
They love to challenge our lungs , thats for sure !

My Best,