Short answer. Yes. Rule 14, Section 23 states that including other grounds alongside lack of jurisdiction over the person in a motion to dismiss is deemed a voluntary appearance. Raising additional grounds beside personal jurisdiction gives up the very objection you were trying to preserve by raising it.
What the law says
The inclusion in a motion to dismiss of other grounds aside from lack of jurisdiction over the person of the defendant shall be deemed a voluntary appearance.
Rule 14, Section 23 — Voluntary appearance. Read the full provision →
Why voluntary appearance matters here
Rule 14, Section 23 opens with the consequence at stake: the defendant's voluntary appearance in the action shall be equivalent to service of summons. Proper service of summons is what typically gives a court jurisdiction over a defendant's person, so a defendant who was never properly served can normally challenge the court's authority over them on that basis. Voluntary appearance short-circuits that: once it happens, it stands in for service that was defective or never completed, and the objection based on improper service is effectively gone.
How a motion to dismiss can trigger it
The rule then states the specific trap your question describes: the inclusion in a motion to dismiss of other grounds aside from lack of jurisdiction over the person of the defendant shall be deemed a voluntary appearance. A motion to dismiss that raises only lack of jurisdiction over the person does not itself waive the objection; that is the one ground you can raise without submitting to the court's jurisdiction. The moment you add any other ground, such as failure to state a cause of action, improper venue, or another defense, alongside the jurisdictional one, the rule treats the whole motion as a voluntary appearance.
What this means for drafting the motion
Because combining grounds this way is deemed a voluntary appearance, a defendant who genuinely wants to preserve an objection to personal jurisdiction has to be careful about what else goes into that same motion. Raising lack of jurisdiction over the person alone keeps the objection alive; folding in additional grounds, even ones that might otherwise seem stronger or more likely to succeed, gives up the personal jurisdiction objection by the rule's own terms. This is a structural consequence of how the motion is composed, not something that depends on which side ultimately wins on the merits of any particular ground raised.
Why this trap exists at all
The rule reflects a basic idea about what it means to submit to a court's authority: asking a court to rule on the merits of a case, even partially, is inconsistent with also telling that same court it has no power over you personally. A motion built solely on lack of jurisdiction over the person asks the court to decide only that narrow question. A motion that also asks the court to weigh in on other grounds, such as the sufficiency of the complaint, invites the court to exercise the very authority the personal-jurisdiction objection was meant to dispute, which is why the rule treats that combination as inconsistent with preserving the objection.