Sena

8000 rows is tiny. Something specific is doing this, and the likeliest suspects in order:

200 conditional formatting rules is a lot, and any that use custom formulas over whole columns re-evaluate on every single edit. Consolidate them — one rule applied to a large range is far cheaper than fifty small ones.

Whole-column references in SUMIFS. SUMIFS(Other!C:C, Other!A:A, $A2) on 8000 rows means eight thousand scans of an unbounded column. Bound the ranges.

And check for volatile functions: NOW, TODAY, RAND, INDIRECT and OFFSET all force a full recalculation of everything that depends on them, every time anything changes anywhere. One TODAY in a helper column feeding 8000 formulas is a classic cause of exactly this.

It is usually one accidental paste or a stray space years ago. Right click the row numbers and delete rows rather than selecting the cells and hitting delete, otherwise the ghost range stays.

Worth knowing it only samples the first few hundred rows to decide, which is why a sheet can work fine for months and then break when someone adds a batch of data at the top.

The underlying issue is that an order reference is not really a number, it is an identifier that sometimes looks like one. If you can, format the whole column as plain text at source so every value is consistently text. Mixed-type columns cause trouble in lookups, pivots and sorting too, not just here.

The reliable workaround for the stubborn ones is BYROW or MAP if you have them. Slower on big ranges but it does what you meant.

Look at your second condition: D2:D > E2. You are comparing a whole column against a single cell. ARRAYFORMULA can only expand to the size of the ranges inside it, and mixing a range with a bare relative single cell in a comparison is one of the ways it silently collapses.

If E2 is genuinely one threshold value, lock it and it will broadcast to every row: D2:D > $E$2. If E is meant to be a column of per-row thresholds, it should be D2:D > E2:E. Right now you have written neither.

The nothing you are seeing below row 2 is the collapse, not the empty-string branch.

For a recurring monthly job, put the raw export on its own tab, untouched, and do all cleaning on a second tab with formulas. Then next month you paste over the raw tab and everything downstream updates. Cleaning in place means redoing the work every month, and eventually pasting into a half-cleaned sheet.

The rename failure mode is exactly what happened last month and why I am rethinking it.