I'm worried a time bar is quietly running against me

Modern contracts increasingly make notice a condition of entitlement: tell us within so many days, in this form, to this address, or the claim can be lost however good it is. NEC contracts do it openly through compensation events, their formal process for claiming time and money; amended JCT contracts often do it in clauses nobody reads until it is too late. A time bar does its work silently, months before anyone argues about it.

If the event has just happened, the priority is simple: find the clause, serve the notice that stops the clock, and argue the merits afterwards. If the deadline may already have passed, the position needs reading carefully, because time bars are construed strictly and not every clause that looks like one actually works as one.