Hi,
Bastion incurs charges simply by existing, whether you use it or not. Same is true of Standard SKU Public IP address. In order to stop charges from accruing for Bastion or Public IP addresses you would need to delete them.
Excerpt from Bastion pricing page:
Azure Bastion is billed hourly from the moment the resource is deployed until the resource is deleted, regardless of outbound data usage. The hourly pricing will be based on the SKU selected, number of scale units configured, and data transfer rates.
Other resources accrue charges simply by existing as well. For example, the managed disk(s) for your VMs. If you examine the pricing page for a specific resource you can find details on how charges are calculated.
If you are unsure about how charges accrue for a specific resource add a comment below and I can help.
Please click Accept Answer and upvote if the above was helpful.
Thanks.
-TP