For Paypal to appear on the product page, you would need to ensure you have Dynamic checkout buttons enabled. As long as Paypal is enabled, it should appear as an option on your cart page or a payment method on the payment page. However, depending on the theme you're using will determine if the button appears on your cart page. Would you mind sharing the URL to your store so I can take a look?
Both Paypal and Afterpay will appear on the payment page of checkout. Afterpay is not an accelerated checkout, so it can not be added to the product page with the dynamic checkout buttons, nor added to the cart page or first page of the checkout. Paypal, on the other hand, should appear on the product page if you have dynamic buttons enabled, and are viewing the product page from an eligible browser. For Paypal to appear on your cart page or first page of the checkout, it would require the proper code within the theme. Are you using a Shopify free theme, or are you using a third-party theme?
I originally had my Amazon Pay and Google pay buttons appearing on my Shopping Cart page, but decided it would be better suited to the checkout page.
It seems that after this change is made, a cookie/cache refresh is necessary on the client side to view these options on the checkout screen. How long does the cookie last for? I am concerned that my customers will not not be able to access these payment methods because they are not aware that they need to clear their cookies or use an incognito browser.
From what I can find, cookies can last up to 12 months before they expire. If customers are not able to see the accelerated checkout options on the cart, or the first page of the checkout, then they will see them on the payment page when they go to complete their purchase. I don't suspect it is a huge issue unless you have a fair amount of returning customers. If that were the case, then you could consider adding proactive messaging to your product/cart pages to help ease the concern of people potentially missing these options.
I'm afraid I can only provide English support here, though, we do offer French Community forums here if you'd prefer. Stripe is seen as a credit card processor, so if it was set up correctly, you should see a field to enter your credit card information when on the payment page of the checkout. It may not indicate that it is Stripe specifically, though it will process the transaction through Stripe. If you do not see a credit card field on the payment page, please share a screenshot of what you do see so I can review it further.
I suspect this is a local ended issue. You can try clearing your cache/cookies and trying again. Though, if you see Paypal appear on your cart page, this could also explain why it does not appear on the first page of the checkout. Typically it would appear on either the cart page or the first page of the checkout, but not both. Your customers will still be able to select the options from the payment page.
I disconnected my PayPal checkout to try to activate the express checkout dynamic button, I also activated Amazon Pay dynamic button and it worked, but now Shopify shows that I am not connected to PayPal. I have tried to activate it several times and every one Shopify says the connection with PayPal was successful, but back in payment providers it shows is not connected, and is not showing anywhere.
That does seem strange! Do you know if you have an ad blocker enabled on your device? If yes, could you disable it and try again? You could also try using a different browser, or your mobile device to see if you can replicate the issue. If using a different browser, or mobile device does not work, and you do not have an ad blocker installed, then let me know. I can reach out via email to verify the account so I can help get this reviewed.