Apple mail -Exchange account on iphone up to date but MBP not syncing

Apple Mail previously seamlessly synced iphone 13 mini and MBP for sometime - but is no longer (since? some sort of OS update). I have an icloud address; a gmail address and an Exchange address (uni email). I have solved problem with gmail (complex, but to do with security settings etc inside gmail - I logged in online to change settings). icloud is OK - but I hardly use it. Exchange account -on iphone 13 mini - where I often work to process emails - is fine. MBP equivalent is not - it is not deleting emails I have processed on iphone mini. I am running the latest OS (Ventura 13.5.1) and IOS (16.6).