Duplicate holdings appear when you have both manual transactions and a broker connection importing the same assets. Delta shows both sets, doubling the position.
Two ways to fix this
Option 1 — Remove your manual transactions: Delete the manual entries for the affected assets and let the broker connection handle importing them. This is the cleanest long-term option if you intend to keep the connection active.
Option 2 — Remove the broker connection: Go to Settings > Connections, tap your broker connection (e.g. Saxo), and choose to delete it. When prompted, select "Remove" to delete all transactions imported by the connection. This restores your portfolio to its state before the connection was added.