how to make custom snippets work?

considering my current config:

{
	settings = {
		["rust-analyzer"] = {
			inlayHints = {
				bindingModeHints = { enable = false },
				chainingHints = { enable = false },
				closingBraceHints = { enable = false },
				closureReturnTypeHints = { enable = "never" },
				discriminantHints = { enable = "never" },
				expressionAdjustmentHints = { enable = "never" },
				lifetimeElisionHints = { enable = "never" },
				parameterHints = { enable = false },
				reborrowHints = { enable = "never" },
				typeHints = { enable = false },
			},
			completion = {
				callable = { snippets = "add_parentheses" },
				autoimport = { enable = false },
				postfix = {
					granularity = {
						group = "module",
					},
					enable = false,
				},
				snippets = {
					custom = {
						Ok = {
							postfix = "ok",
							body = "Ok(${receiver})",
							description = "Wrap the expression in a `Result::Ok`",
							scope = "expr",
						},
						["Box::pin"] = {
							postfix = "pinbox",
							body = "Box::pin(${receiver})",
							requires = "std::boxed::Box",
							description = "Put the expression into a pinned `Box`",
							scope = "expr",
						},
						["Arc::new"] = {
							postfix = "arc",
							body = "Arc::new(${receiver})",
							requires = "std::sync::Arc",
							description = "Put the expression into an `Arc`",
							scope = "expr",
						},
						Some = {
							postfix = "some",
							body = "Some(${receiver})",
							description = "Wrap the expression in an `Option::Some`",
							scope = "expr",
						},
						Err = {
							postfix = "err",
							body = "Err(${receiver})",
							description = "Wrap the expression in a `Result::Err`",
							scope = "expr",
						},
						["Rc::new"] = {
							postfix = "rc",
							body = "Rc::new(${receiver})",
							requires = "std::rc::Rc",
							description = "Put the expression into an `Rc`",
							scope = "expr",
						},
					},
				},
			},
			imports = { prefix = "crate" },
			diagnostics = {
				disabled = { "inactive-code", "unlinked-file", "type-mismatch", "macro-error" },
				enable = true,
				experimental = { enable = false },
			},
			procMacro = {
				enable = false,
				attributes = { enable = false },
			},
			checkOnSave = true,
			lens = {
				enable = false,
				run = { enable = false },
				references = { method = { enable = false } },
				implementations = { enable = false },
			},
			check = {
				allTargets = true,
				extraArgs = {},
			},
			cargo = {
				buildScripts = { enable = false },
				features = {},
			},
			runnables = { extraArgs = {} },
			rustfmt = {
				extraArgs = {},
				rangeFormatting = { enable = true },
			},
			trace = { server = "off" },
		},
	},
	on_attach = rust_analyzer_on_attach,

while I try to use a.pinbox or a.ok etc, it doesn't do anything or propose me anything. This feature is a bit wierd for me, it worked me years ago then suddenly it disappered and I cannot use them anymore

Start by reproducing the reported custom-snippet configuration in a Rust buffer, trying a.pinbox and a.ok with the supplied rust-analyzer settings. Check whether the snippets are offered at all and document the configuration or environment detail that determines whether the expected suggestions appear.