I may be having the same problem. I can no longer access my site. I got this message:
An error of type E_ERROR was caused in line 244 of the file /hermes/bosnacweb04/bosnacweb04af/b1258/ipg.grumpyjohnnet/wp-content/plugins/jetpack/vendor/automattic/jetpack-connection/legacy/class-jetpack-signature.php. Error message: Uncaught Error: Call to undefined function ctype_digit() in /hermes/bosnacweb04/bosnacweb04af/b1258/ipg.grumpyjohnnet/wp-content/plugins/jetpack/vendor/automattic/jetpack-connection/legacy/class-jetpack-signature.php:244
Stack trace:
#0 /hermes/bosnacweb04/bosnacweb04af/b1258/ipg.grumpyjohnnet/wp-content/plugins/jetpack/vendor/automattic/jetpack-connection/src/class-client.php(143): Jetpack_Signature->sign_request('pkqR(Ueldk^!*8&...', 1628648102, 'Zn00wHJOYK', '5kLaf9TlRySjcXb...', 'POST', 'https://jetpack...', '
