JQL Wildcard search with 2 words from summary- No proper results

[NRAP]

We're on server version 7.2.15. There are around 400 tickets in a project with summary  "USA_PM1_Teams-xyz..." or "USA_SLT_Teams-abc...". The common pieces from the summary are "USA" and "Teams" so I've tried the search in 3 ways which gave me different results in each: 

1. project = ABC and summary ~ "USA*Teams*"

which pulls just the tickets with summary "USA_PM1_Teams-xyz..."

2. project = ABC and summary ~ "USA && Teams"

which pulls just the tickets with summary "USA_SLT_Teams-abc..."

3. Project = ABC and summary ~ "USA_PM_Teams" or Project = ABC and summary ~ "USA_SLT_Teams" 

which pulls the all the results correctly.

We're now using (3) but the whole teams is curious to know why the queries (1) & (2) aren't pulling the whole list.

Or

If the query is incorrect, why? where? and what is the correction needed to fix it?

Please post any thoughts or suggestions. Thanks in advance!

[Payne]

Very strange; I get the exact same results as you. I have no idea why.