I just tried another order for NUGX on Schwab, and it said that this order can't be placed online, to call to place the order. I guess that would be expected once a stock hits the OTC Expert Market. I also think that the PQE (Proprietary Quote Eligibility) Status of "Yes" allows GNBT to keep trading. NUGX PQE Status is "No".

OTC - Understanding the Expert Market
https://blog.otcmarkets.com/2021/03/25/unders...rt-market/

OTC - NUGX Quote page
https://www.otcmarkets.com/stock/NUGX/quote

OTC - GNBT Quote page
https://www.otcmarkets.com/stock/GNBT/quote