Paypal "name lookup timed out" Error duting checkout since May 2018

Since a few days ago, I've been getting these error messages (below) when people try to pay via Paypal Express or Paypal Pro with credit card. It's happening to almost every transaction via Paypal or Credit Card (via Paypal Pro).
I've made no changes to the code for a long time, and my host tells me no changed have been made either.
I've tested it myself, and also get this error on the checkout page. The error comes up immediately, so it's not actually a timeout issue.

Any ideas anyone?

This is the message, personal details replaced with XXXX:

Dear store owner,
An error occurred when attempting to initiate the payment-validation transaction. As a courtesy, only the error "number" was shown to your customer. The details of the error are shown below.

(6) name lookup timed out

Zen Cart message: [] - (6) name lookup timed out

Problem occurred while customer 3433 XXXXwas attempting checkout with PayPal Website Payments Pro.

Transaction Response Details: Array
(
[] =>
[CURL_ERRORS] => (6) name lookup timed out
)

Transaction Submission: Array
(
[ACCT] => ************2448
[AMT] => 29.60
[CARDISSUE] =>
[CITY] => Esk
[COUNTRYCODE] => AU
[CREDITCARDTYPE] => Visa
[CUSTOM] => DP-3433-1526020101
[CVV2] => ***
[EMAIL] => XXXX
[EXPDATE] => 032020
[FIRSTNAME] => XXXX
[INVNUM] => 3433-1526020101-[OOAKTableTennisShop]
[IPADDRESS] => XXXX
[ITEMAMT] => 26.60
[LASTNAME] => XXXX
[L_AMT0] => 28.00
[L_AMT1] => -1.40
[L_NAME0] => SpinLord Stachelfeuer OX - ultra slow, high disruption! [992] Color: Black
[L_NAME1] => Credits applied, including discount coupons, gift certificates, etc
[L_QTY0] => 1
[L_QTY1] => 1
[NOTIFYURL] => https://tabletennisshop.com.au/ipn_main_handler.php
[PAYMENTACTION] => Sale
[PAYMENTREQUEST_0_PAYMENTACTION] => Sale
[PHONENUM] => 0400047222
[SHIPPINGAMT] => 3.00
[SHIPTOCITY] => Esk
[SHIPTOCOUNTRYCODE] => AU
[SHIPTONAME] => XXXX
[SHIPTOSTATE] => QLD
[SHIPTOSTREET] => XXXX
[SHIPTOZIP] => 4312
[STATE] => QLD
[STREET] => XXXX
[ZIP] => 4312
[METHOD] => DoDirectPayment
[CURRENCYCODE] => AUD
)


Problem occurred while customer #3433 -- XXXX -- was attempting checkout.

Aplogies, I guess this post should be in the Paypal Pro section, can a moderator please move it?

Anyone please?

The first item in the "Similar Threads" (scroll down the screen a bit) seems to address your issue.