diff --git a/test/infra/control/run-tests-isolated.bash b/test/infra/control/run-tests-isolated.bash
index ded42a880..689df1854 100755
--- a/test/infra/control/run-tests-isolated.bash
+++ b/test/infra/control/run-tests-isolated.bash
@@ -12,7 +12,7 @@ export INFRA_ID="${INFRA_ID:-dev-$USER}"
 
 # 1. Determine Required Infras
 INFRAS_TO_CHECK=""
-BASE_GROUP="${TAP_GROUP%%-g[0-9]*}" # Strip -g1, -g2 etc.
+BASE_GROUP=$(echo "${TAP_GROUP}" | sed -E "s/[-_]g[0-9]+.*//") # Strip -g1, -g2, _g1, _g2 etc.
 
 if [ -n "${TAP_GROUP}" ]; then
     if [ -f "${WORKSPACE}/test/tap/groups/${TAP_GROUP}/infras.lst" ]; then
@@ -142,7 +142,6 @@ docker run \
 # This runs before the test runner container is removed, allowing cleanup
 # of ProxySQL-specific configuration while admin is still accessible
 if [ -n "${TAP_GROUP}" ]; then
-    BASE_GROUP="${TAP_GROUP%%-g[0-9]*}"
     PRE_CLEANUP_HOOK="${WORKSPACE}/test/tap/groups/${TAP_GROUP}/pre-cleanup.bash"
     if [ ! -f "${PRE_CLEANUP_HOOK}" ]; then
         PRE_CLEANUP_HOOK="${WORKSPACE}/test/tap/groups/${BASE_GROUP}/pre-cleanup.bash"
diff --git a/test/tap/groups/ai-g1/env.sh b/test/tap/groups/ai-g1/env.sh
index 1ea85268a..04635ab7a 100644
--- a/test/tap/groups/ai-g1/env.sh
+++ b/test/tap/groups/ai-g1/env.sh
@@ -1,3 +1,4 @@
+# shellcheck shell=bash
 # AI-g1 Subgroup Environment Configuration
 # Sources the parent ai group configuration
 
diff --git a/test/tap/groups/ai/README.md b/test/tap/groups/ai/README.md
index ec54af526..a5f8dc8cd 100644
--- a/test/tap/groups/ai/README.md
+++ b/test/tap/groups/ai/README.md
@@ -93,6 +93,7 @@ source test/infra/common/env.sh
 export INFRA_ID="ai-harvest-$(date +%s)"
 export TAP_GROUP="ai-g1"
 export TEST_PY_TAP_INCL="test_mcp_static_harvest-t"
+export WORKSPACE=$(pwd)
 
 source test/infra/common/env.sh
 ./test/infra/control/ensure-infras.bash
@@ -106,6 +107,7 @@ source test/infra/common/env.sh
 export INFRA_ID="ai-discovery-$(date +%s)"
 export TAP_GROUP="ai-g1"
 export TEST_PY_TAP_INCL="test_mcp_llm_discovery_phaseb-t"
+export WORKSPACE=$(pwd)
 
 source test/infra/common/env.sh
 ./test/infra/control/ensure-infras.bash
@@ -119,6 +121,7 @@ source test/infra/common/env.sh
 export INFRA_ID="ai-claude-$(date +%s)"
 export TAP_GROUP="ai-g1"
 export TEST_PY_TAP_INCL="test_mcp_claude_headless_flow-t"
+export WORKSPACE=$(pwd)
 
 source test/infra/common/env.sh
 ./test/infra/control/ensure-infras.bash
diff --git a/test/tap/groups/ai/env.sh b/test/tap/groups/ai/env.sh
index de39e7265..52b6152e9 100644
--- a/test/tap/groups/ai/env.sh
+++ b/test/tap/groups/ai/env.sh
@@ -1,3 +1,4 @@
+# shellcheck shell=bash
 # AI TAP Group Environment Configuration
 # Defines the primary targets for AI/MCP tests using standard test/infra/ pattern
 
diff --git a/test/tap/groups/ai/mcp-config.sql b/test/tap/groups/ai/mcp-config.sql
index 87c651a19..f106b302e 100644
--- a/test/tap/groups/ai/mcp-config.sql
+++ b/test/tap/groups/ai/mcp-config.sql
@@ -26,9 +26,9 @@ LOAD PGSQL SERVERS TO RUNTIME;
 SAVE PGSQL SERVERS TO DISK;
 
 -- Configure frontend users for TAP tests
-INSERT OR IGNORE INTO mysql_users (username, password, active, default_hostgroup, comment)
+INSERT OR REPLACE INTO mysql_users (username, password, active, default_hostgroup, comment)
     VALUES ('${TAP_MYSQLUSERNAME}', '${TAP_MYSQLPASSWORD}', 1, 0, 'ai local');
-INSERT OR IGNORE INTO mysql_users (username, password, active, default_hostgroup, comment)
+INSERT OR REPLACE INTO mysql_users (username, password, active, default_hostgroup, comment)
     VALUES ('testuser', 'testuser', 1, 0, 'ai local');
 LOAD MYSQL USERS TO RUNTIME;
 SAVE MYSQL USERS TO DISK;
diff --git a/test/tap/groups/ai/seed-mysql.sql b/test/tap/groups/ai/seed-mysql.sql
index 6c2e1791e..342563197 100644
--- a/test/tap/groups/ai/seed-mysql.sql
+++ b/test/tap/groups/ai/seed-mysql.sql
@@ -1,6 +1,6 @@
 -- AI Group MySQL Test Data Seeding
 -- Creates tables needed by AI/MCP tests
--- This is executed by docker-mysql-post.bash when TAP_GROUP starts with 'ai'
+-- This is executed by setup-infras.bash as part of AI group infrastructure setup
 
 CREATE DATABASE IF NOT EXISTS test;
 USE test;
diff --git a/test/tap/groups/ai/seed-pgsql.sql b/test/tap/groups/ai/seed-pgsql.sql
index 7208c9a47..cf14fedad 100644
--- a/test/tap/groups/ai/seed-pgsql.sql
+++ b/test/tap/groups/ai/seed-pgsql.sql
@@ -1,6 +1,6 @@
 -- AI Group PostgreSQL Test Data Seeding
 -- Creates tables needed by AI/MCP tests
--- This is executed by docker-pgsql-post.bash when TAP_GROUP starts with 'ai'
+-- This is executed by setup-infras.bash as part of AI group infrastructure setup
 
 CREATE TABLE IF NOT EXISTS public.tap_pgsql_static_accounts (
   account_id INT PRIMARY KEY,
diff --git a/test/tap/groups/ai/setup-infras.bash b/test/tap/groups/ai/setup-infras.bash
index 1daa6aecb..4bcf43096 100755
--- a/test/tap/groups/ai/setup-infras.bash
+++ b/test/tap/groups/ai/setup-infras.bash
@@ -34,6 +34,17 @@ if [ -z "${DEFAULT_MYSQL_INFRA:-}" ] || [ -z "${DEFAULT_PGSQL_INFRA:-}" ]; then
     fi
 fi
 
+# Validate that required infrastructure names were resolved
+if [ -z "${DEFAULT_MYSQL_INFRA:-}" ]; then
+    echo "ERROR: Could not resolve DEFAULT_MYSQL_INFRA (check ${SCRIPT_DIR}/infras.lst)"
+    exit 1
+fi
+
+if [ -z "${DEFAULT_PGSQL_INFRA:-}" ]; then
+    echo "ERROR: Could not resolve DEFAULT_PGSQL_INFRA (check ${SCRIPT_DIR}/infras.lst)"
+    exit 1
+fi
+
 export ROOT_PASSWORD=$(echo -n "${INFRA_ID}" | sha256sum | head -c 10)
 PROXY_CONTAINER="proxysql.${INFRA_ID}"