https://github.com/rrweb-io/rrweb/pull/866/files

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@highlight-run/rrweb",
-  "version": "1.1.16",
+  "version": "1.1.17",
   "description": "record and replay the web",
   "scripts": {
     "test": "npm run bundle:browser && cross-env TS_NODE_CACHE=false TS_NODE_FILES=true mocha -r ts-node/register -r ignore-styles -r jsdom-global/register test/**.test.ts",

src/snapshot/snapshot.ts

@@ -585,7 +585,12 @@ function serializeNode(
       if (isStyle && textContent) {
         try {
           // try to read style sheet
-          if ((n.parentNode as HTMLStyleElement).sheet?.cssRules) {
+          if (n.nextSibling || n.previousSibling) {
+            // This is not the only child of the stylesheet.
+            // We can't read all of the sheet's .cssRules and expect them
+            // to _only_ include the current rule(s) added by the text node.
+            // So we'll be conservative and keep textContent as-is.
+          } else if ((n.parentNode as HTMLStyleElement).sheet?.cssRules) {
             textContent = stringifyStyleSheet(
               (n.parentNode as HTMLStyleElement).sheet!,
             );