A March 9, 2020 SEVP Guidance Notice acknowledges that CPT and OPT workplace changes will occur as a result of COVID-19:

"SEVP intends to be flexible with temporary adaptations.  in all cases, schools and STUDENTS [emphasis added] need to document any decisions made and be able to provide this information to SEVP upon request.  Similarly, changes to workplace requirements may impact non-immigrant students engaging in practical training.  SEVP encourages such students to consult with their employer to seek alternative ways to maintain employment, such as teleworking or other arrangements."

It will be the responsibility of the student to keep a logbook of all directives given to them by the employer to work at home and to records those dates in a diary, calendar or logbook of some sort.