Error: Will not follow more than 1 redirects - how to fix?

I have previously used WP2Static 6.6.7 to push to S3. A very old version!
I am testing version 7.1.7 (S3 and Zip add-ons active).

Options: only Detect Pages; Deployment url https://localhost

As soon as I click ‘Generate static site’ I get a 500 error:

[14-Dec-2022 13:28:25 UTC] PHP Fatal error:  Uncaught WP2StaticGuzzleHttp\Exception\TooManyRedirectsException: Will not follow more than 1 redirects in /wp-content/plugins/wp2static/vendor/leonstafford/wp2staticguzzle/src/RedirectMiddleware.php:147
Stack trace:
#0 /wp-content/plugins/wp2static/vendor/leonstafford/wp2staticguzzle/src/RedirectMiddleware.php(88): WP2StaticGuzzleHttp\RedirectMiddleware->guardMax()
#1 /wp-content/plugins/wp2static/vendor/leonstafford/wp2staticguzzle/src/RedirectMiddleware.php(73): WP2StaticGuzzleHttp\RedirectMiddleware->checkRedirect()
#2 /wp-content/plugins/wp2static/vendor/leonstafford/wp2staticpromises/src/FulfilledPromise.php(41): WP2StaticGuzzleHttp\RedirectMiddleware->WP2StaticGuzzleHttp\{closure}()
#3 /wp-content/plugins/wp2static/vendor/leonstafford/wp2staticpromises/src/TaskQueue.php(48): WP2StaticGuzzleHttp\Promise\FulfilledPromise::WP2StaticGuzzleHttp\Promise\{closure}()
#4 /wp-content/plugins/wp2static/vendor/leonstafford/wp in /wp-content/plugins/wp2static/vendor/leonstafford/wp2staticguzzle/src/RedirectMiddleware.php on line 147

The log shows:

2022-12-14 13:14:54: Starting to detect WordPress site URLs.
2022-12-14 13:14:54: Starting URL detection
2022-12-14 13:14:54: Running WP2Static in Headless mode
2022-12-14 13:14:54: Running full workflow from UI

I edited the guardMax() function to explicitly set $current and $max to 100 to see if that fixed things. It didn’t.

        $current = $options['__redirect_count']
            ?? 0;
$current = 100;
        $options['__redirect_count'] = $current + 1;
        $max = $options['allow_redirects']['max'];
$max = 100;
        if ($options['__redirect_count'] > $max) {
            throw new TooManyRedirectsException("Will not follow more than {$max} redirects", $request, $response);
        }

How should I troubleshoot this?