They’re just titles. They may perform the exact same job.
Salary will be locale-specific. Asking here won’t be helpful to your personal situation.
The title 'Solutions Architect' and 'Architect' can often be used interchangeably in the tech industry, but there can be subtle differences depending on the company and its structure. Generally speaking, a 'Solutions Architect' often implies a role that is more focused on designing specific solutions for specific business problems, often working closely with clients or stakeholders. An 'Architect', on the other hand, may have a more overarching role, looking at system design and architecture at a higher level, and may not be as tied to specific solutions.
As for which is more robust or higher-paying, that can depend greatly on the specific job, the company, the industry, and the geographical location. It's also important to note that job titles can sometimes be misleading, and the actual responsibilities and compensation can vary greatly. Therefore, it's always a good idea to look at the job description and responsibilities, and to ask about compensation during the interview process. Also, websites like Glassdoor or Payscale can provide some insight into average salaries for these roles in different locations and industries.
In my experience solution architects are client facing and work with external partners on business solutions. Whereas architects are within engineering and responsible for the internal tech / system.
What's more robust or higher paying generally probably doesn't matter as much as what you are more suited for.
I would expect Solutions Architect might have pay tied to sales commission. And sales commissions can be boom or bust.
"Solutions" = sales or sales adjacent.
I've never seen a title of "architect" at any of the companies I've worked at in the past fifteen years.
In my experience, Solutions Architects are on the services side, while Architect (no modifier) are on the engineering side. Solutions Architects put together customer specific solutions from a suite of technologies, while Architects are responsible for the general development and maintenance of said technologies. Solutions Architects may also work directly for the company that build the technology, or as partner who offers services and expertise.
They are completely different roles with different tracts.