I try to avoid faxes, or to follow up with a mailed paper copy, but last year neither method was reliable.  Meanwhile, I'll trade your 86yo client for my 90yo, who just received an IRS notice rejecting her 2019 return, filed more than a year ago, because they say her SSN belongs to someone who is deceased.  This did not come as a surprise to her, not only because she is aware she is still alive but because the same thing happened with her 2015 return.  It took about a year to resolve that one (Taxpayer Advocate refused to help).  She thinks this is probably why she did not receive EIP2 and EIP3, and she's probably right.  But EIP2 simply reduced the balance due on her 2020 return -- and there was no refund on her 2019 return either, so what are they going to do to her if they think she's dead?  

Meanwhile, to continue the IRS copier shortage story, it turns out part of the problem is that they are running their own publishing operation.  They have to print instructions for new employees because they can't afford to issue tablets or laptops with training manuals:

"During our walkthroughs, local management has expressed frustration and concern with the ability to fill needed positions. Furthermore, once a person is hired, additional training needs to be completed before these new hires are able to assist with resolving current and backlogged inventories. It is also difficult to find working copiers (as noted previously) to be able to prepare training packages for the new hires. Many of these new hires are not provided a computer, and hard copies of the training material are the main training resource available."