This language appeared in the latest 10-Q:
"Depending on the Company’s public float, the Company may not be eligible to utilize Form S-3 for future primary offerings of its securities following the filing of its Annual Reports on Form 10-K in 2019 and 2020. The Company anticipates that in the future, if it were to no longer eligible to use Form S-3, that it may utilize Form S-1 to register the sale of its securities, including through future financing agreements with Aspire Capital."
Consider the possibility that the explanation for today's post-effective amendment is related to that.