diff --git a/docs/en/observability/apm/known-issues.asciidoc b/docs/en/observability/apm/known-issues.asciidoc
index e5fa299dbc..4f1cbb22ae 100644
--- a/docs/en/observability/apm/known-issues.asciidoc
+++ b/docs/en/observability/apm/known-issues.asciidoc
@@ -68,6 +68,28 @@ In both cases, the settings of APM Integration are maintained. However, these wo
 
 This bug will be fixed in 8.19.1 and 9.1.1.
 
+[discrete]
+== HTTP/2 connections can fail with strict clients due to framing errors
+
+_Elastic Stack versions: >=8.19.12 and <8.19.15_
+
+APM Server can fail HTTP/2 requests from strict clients (for example, curl/nghttp2) after ALPN negotiates `h2`.
+
+In affected versions, APM Server can send inconsistent SETTINGS values at connection start (an initial empty/default SETTINGS frame followed by a different SETTINGS set), and strict clients treat that sequence as an HTTP/2 protocol error and close the connection.
+
+When this occurs, clients can report framing/connection errors such as `Error in the HTTP2 framing layer` or `Failure when receiving data from the peer`. Browser-based HTTP requests from the RUM agent can also fail with `net::ERR_HTTP2_PROTOCOL_ERROR`.
+
+When clients close the HTTP/2 connection due to this issue, APM Server logs an error: `http2: received GOAWAY [FrameHeader GOAWAY len=66], starting graceful shutdown`.
+
+For more information, check https://github.com/elastic/apm-server/issues/20887[issue #20887].
+
+There are two workarounds:
+
+* Use HTTP/1.1 to communicate with APM Server on affected versions.
+* If clients require HTTP/2, place a non-strict load balancer in front of APM Server and terminate HTTP/2 at the load balancer (for example, on some load balancers this can be done by switching from TCP mode to HTTP mode).
+
+This bug will be fixed in 8.19.15.
+
 [discrete]
 == Tail Sampling may not compact / expired TTLs as quickly as desired, causing increased storage usage.