Use tag svg in ionic

Hello everyone. I’m newcomer in ionic and I need help of experts) I have two pages, which have common tabs for movement to the one of these pages. On first page is bar chart, on the second page is pie chart, which are built by click on button. Each page have tag svg with height and weght of the chart. When I’m on bar chart page and click “build chart” - bar chart are built on this page, when I move to the pie chart page and click “build chart” - on the page nothing is happend, but pie chart are built on the bar chart page. Tell me why, if for each chart is page with html code and .ts file, they are built on one, but not on own page?