SSB Whip antenna blind spot?

[kcj]

Preface this by I am NEW to the ssb world, and most of what I know I have absorbed from this site. Many thanks to all!

In the central exumas listening to Chris Parker on 4 MHz. I hear a call from a nearby anchorage and Chris hears it loud and clear. I call shortly thereafter and Chris cannot hear me, but someone (I believe) to the south of me hears me clearly and relays for me. Call is completed via relay.

Other bkgd, I have a new to me cat with a whip antenna mounted next to the aluminum solar panel structure. The solar panel structure is about 1/3 the height of the whip. I have done radio checks on 8mhz with Chris and they have worked fine. Have an icom 802 and AT400 tuner. Whip is installed two feet or less from tuner. DSC tests have been successful, but only at certain times of day--I assumed because of MHz propagation issues.

Query---what is causing this tx anomaly? can my solar panel structure be blocking my ssb tx signal in certain directions (the structure was between the antenna and Florida...)?

Thanks in advance!