Libre Office Calc update misbehavior

[Geoffrey Combes]

I use Calc spreadsheet for my annual budget. It's a complicated and 
detailed budget that I developed myself.
There is a summary page in which totals from detail pages are recorded.
For example the total for the Health page in cell D5 is transferred to 
the Summary page for Health where the cell appears as Health.D5 (a 
figure in $AU of course).
Occasionally, not often, an update for Libre Office is downloaded and 
installed. Lately I find that some, not all, of the transfers from 
detailed pages to the Summary page have changed such that the page 
reference disappears. In the above example the Summary page cell for 
Health now is recorded as D5 (not Health.D5).  One would expect the $ in 
this cell to be what is shown in D5 of the Summary page. But it isn't - 
it continues to record what is in D5 of the Health page. That is until 
something is changed and on the detail page and then I get wrong data on 
the Summary page.
This misbehaviour can go unnoticed and causes havoc on the one important 
page of my budget - the Cash Flow page (a forward estimate), the 
accuracy of which I rely on.

Has anyone noticed this misbehaviour in Calc after updating, or can shed 
light on the phenomenon?
I should mention that I often fix the cell using the $ symbol; thus, in 
the above example, Health.D5 reads Health.$D$5 because I want to copy 
the formula through other columns without changing the cell name. I use 
two $ symbols, I may only need to use one. I wonder too if the $ symbol 
in the cell name is part of the problem.

Your advice would be appreciated. Believe me, correcting this 
misbehaviour is extremely tedious.

Geoffrey Combes