traffic drop after underscore to dashes change

[spok]

Hello,
I have made the change from underscores to dashes [_ => -]
via external file.
thsi is the rule:

RewriteCond %{THE_REQUEST} (application|product) [NC]
RewriteRule ^([^_]+)_ /underscores.php [L]

and the external file:
function curPageURL() {
$pageURL = 'http';
if ($_SERVER["HTTPS"] == "on") {$pageURL .= "s";}
$pageURL .= "://";
if ($_SERVER["SERVER_PORT"] != "80") {
$pageURL .= $_SERVER["SERVER_NAME"].":".$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"];
} else {
$pageURL .= $_SERVER["SERVER_NAME"].$_SERVER["REQUEST_URI"];
}
return $pageURL;
}
$pageURL = curPageURL();
$newURL = str_replace('_','-',$pageURL);
$RedirectionUrl = $newURL;
header("HTTP/1.1 301 Moved Permanently");
header("Location: $RedirectionUrl");

I have noticed a traffic drop. The sitemap has stayed as it was (with underscores) so spiders can find the new address.
Can you please tell me what did I do wrong? Or is this temporary?
thx,

spok

[g1smd]

It is temporary. Make sure that no request can ever result in a multiple-step redirection chain.

Update your sitemap as soon as possible. The sitemap should include valid URLs, not URLs that redirect.

[spok]

thx g1smd,
question: if I change sitemap and all links on page, the spiders will see only new pages and will not connect new links with old links (underscores vs dashes). Or the steps are change urls and sitemaps, keep web as it was?
thank you

spok