LSP with Intelephense and Phpactor doesn't recognise WordPress functions

Language Server Protocol (LSP)
1

I want to use both Intelephense and Phpactor with the Neovim LSP because Phpactor seems to be better in code refactoring. But within my WordPress plugins code I get messages like Function "register_activation_hook" not found for all WordPress functions. The WordPress installation lives in `/var/www/dev.

Where is my configuration problem?

local capabilities = vim.lsp.protocol.make_client_capabilities()
capabilities = require( "cmp_nvim_lsp" ).default_capabilities( capabilities )

lspconfig.intelephense.setup( {
	capabilities = capabilities,
	settings = {
		intelephense = {
			files = {
				maxSize = 5000000, -- Increase max file size if needed
				associations = { "**/*.php", "**/wp-includes/**/*.php", "**/wp-admin/**/*.php" }, -- Explicitly include WordPress files
				exclude = { "**/node_modules/**", "**/vendor/**", "**/.git/**" },
			},
			environment = {
				includePaths = { "/var/www/dev/wp-includes", "/var/www/dev/wp-admin" }, -- Set to your WordPress installation
			},
			stubs = {
				"wordpress", "wordpress-globals", "wp-cli", "woocommerce", "acf-pro",
				"bcmath", "bz2", "calendar", "Core", "curl", "date", "dom", "genesis", "json", "libxml", "mbstring", "openssl",
				"pcre", "reflection", "session", "simplexml", "sodium", "spl", "standard", "xml", "zlib", "zip",
			},
			diagnostics = {
				enable = true,
			},
			completion = {
				fullyQualifyGlobalConstants = true,
				insertUseDeclaration = true,
			},
		},
	},
} )

lspconfig.phpactor.setup( {
	capabilities = capabilities,
	init_options = {
		["language_server_phpstan.enabled"] = false, -- Disable PHPStan analysis if not need
		ed
		["language_server_psalm.enabled"] = false,   -- Disable Psalm if not used
	},
	handlers = {
		["textDocument/completion"] = function() end, -- Disable Phpactor completion (use In
		telephense)
		["textDocument/hover"] = function() end,      -- Disable Phpactor hover (use Intelep
		hense)
		["textDocument/definition"] = function() end, -- Disable go-to-definition in Phpacto
		r
		["textDocument/references"] = function() end, -- Disable references (use Intelephens
		e)
		["textDocument/documentSymbol"] = function() end, -- Disable symbol indexing (use In
		telephense)
		["workspace/symbol"] = function() end, -- Prevent Phpactor from taking over workspac
		e symbols
	},
} )