Magento 2.4 checkout issues

In our Magento 2.4 with 2 websites (www.discountmedicalsupplies.com and www.discountchiropracticsupplies.com) store clients intermittently can not place orders from frontend and our clerks cannot make orders form backend at all, site keeps loading and do not do anything. We are using Paypal Payments Pro and paypal is not getting the transactions from their side. We need a solution and specific technical details about the solution at the end.