TLA+ simulation failure observed on main

[Heidi Howard]

Reminder to myself to investigate https://dev.azure.com/MSRC-CCF/CCF/_build/results?buildId=81164&view=results

[Markus Alexander Kuppe]

On first sight, looks like a spec bug:

Error: Evaluating invariant LogInv failed.
The third argument of SubSeq must be in the domain of its first argument:
<< [term |-> 2, contentType |-> Reconfiguration, configuration |-> {n4}],
   [term |-> 2, contentType |-> Signature],
   [term |-> 2, contentType |-> Entry, request |-> 42],
   [term |-> 2, contentType |-> Signature],
   [term |-> 2, contentType |-> Entry, request |-> 42] >>
, but instead it is
8