I have been trying the PayIn4 service and had a few go through and finish on time, no delays but on recent attempts at eBay, GoodGuys, Bing Lee where there is a specific sales option to use PayIn4 I go through the process then get the message " cannot offer PayIn4 , please use another method"
or some wording to that effect.
I asked PayPal customer service and was advised there was no limitations on my account, I have used paypal for a long time, so I do not understand what is going on. The items I tried to purchase all meet the criteria etc.
Pay in 4 is integrated into PayPal Checkout system. When you attempt to pay with PI4, the system does some internal checks to determine if it’s offered or not. If it’s not, use another method to pay for now. You may be approved again in the future. It could be risk based to a thing where you leaning on it too much lately and want to give some other account the credit.