Combining Page-derived dimensions such as "Full URL" or "Path" with Search query can cause seemingly large discrepancies. However this is often expected and caused by the query configuration, as impressions can be counted by URL or by property.
These discrepancies are particularly common when summing impressions without taking the underlying data structure (query configuration or data warehouse schema) into account.
If we look at the property-level data for one search query:
It matches with what you see in Google Search Console:
However if you add a Page-derived dimension into the query, the sum of impressions get inflated significantly:
As noted above, this behaviour is expected and can be replicated in Google Search Console reporting UI as well:
You can find more exact details regarding this from the link below: