JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE HTML>
<script src="https://sapui5.netweaver.ondemand.com/resources/sap-ui-core.js"
				id="sap-ui-bootstrap"
				data-sap-ui-libs="sap.m,sap.ui.commons,sap.ui.table"
				data-sap-ui-theme="sap_bluecrystal">
		</script>

		<!-- add sap.ui.table,sap.ui.ux3 and/or other libraries to 'data-sap-ui-libs' if required -->

		<script>
				sap.ui.localResources("learning");
				var view = sap.ui.view({id:"idfirst1", viewName:"learning.first", type:sap.ui.core.mvc.ViewType.JS});
				view.placeAt("content");
		</script>

	</head>
	<body class="sapUiBody" role="application">
		<div id="content"></div>
	</body>
</html>

JavaScript

var mdata1 =[
		            {id:1,text:"sel1",},
		            {id:2,text:"sel2"},
		            {id:3,text:"sel3"}
		            ];

		
		var mdata2 =[
		            {id:1,text:"sap",},
		            {id:2,text:"scn"},
		            {id:3,text:"community"}
		            ];
		
		var oModel1 = new sap.ui.model.json.JSONModel();
		oModel1.setData(mdata1);
		sap.ui.getCore().setModel(oModel1,"oModel1");
		
		var oComboBox1 = new sap.ui.commons.ComboBox("combo1",{ 
            // even if you replace with sap.m.ComboBox it works fine
		items:{
			path:"oModel1>/",
			template: new sap.ui.core.ListItem({
			key:"{oModel1>id}",
			text:"{oModel1>text}"
		}),
			
		}
		});
		
		var oModel2 = new sap.ui.model.json.JSONModel();
		oModel2.setData(mdata2);
		sap.ui.getCore().setModel(oModel2,"oModel2");

		var oComboBox2 = new sap.ui.commons.ComboBox("combo2",{
            // even if you replace with sap.m.ComboBox it works fine
		items:{
			path:"oModel2>/",
			template:new sap.ui.core.ListItem({
			key:"{oModel2>id}",
			text:"{oModel2>text}"
		}),
			
		},	
		});
		
		var oComboBox1 = new sap.ui.layout.VerticalLayout({
			content:[oComboBox1,oComboBox2],
		});
oComboBox1.placeAt("content");