A blockchain bridge, otherwise known as a cross-chain bridge, connects two blockchains and allows users to send cryptocurrency from one chain to the other. Basically, if you have bitcoin but want to spend it like Ethereum, you can do that through the bridge (source: Liquid).
Cryptio supports bridges to Ethereum. We run our own node & are confident in its accuracy and completeness. On Polygon, however, owing to the current version of our connector, we cannot see bridged transactions on the network. This can result in 1 side of the transaction missing from Cryptio.
What to do
Currently, if bridge transactions are missing, best practice is to import missing transactions into Cryptio via our custom CSV import method. Head to the appropriate blockchain scanner to identify what needs importing.
E.g, deposits on Polygon which would need importing via CSV to solve 'missing volume' cost basis errors: