diff --git a/tools/ui/src/lib/stores/models/props.svelte.ts b/tools/ui/src/lib/stores/models/props.svelte.ts
index f7c20513a2..5b531d54a0 100644
--- a/tools/ui/src/lib/stores/models/props.svelte.ts
+++ b/tools/ui/src/lib/stores/models/props.svelte.ts
@@ -14,12 +14,17 @@ import { MODEL_PROPS_CACHE } from '$lib/constants';
 import { FileTypeCategory, ModelModality } from '$lib/enums';
 import { PropsService } from '$lib/services/props.service';
 // direct imports between stores, not via the barrel, to avoid circular deps
+import { backendsStore } from '$lib/stores/backends.svelte';
 import { serverStore } from '$lib/stores/server.svelte';
 // deep imports, not the '$lib/utils' barrel: it re-exports modules that reach back
 // into the stores, and going through it here would read a half-built module
 import { TTLCache } from '$lib/utils/cache-ttl';
 import { detectThinkingSupport } from '$lib/utils/chat-template-thinking-detector';
-import { SvelteSet } from 'svelte/reactivity';
+import { rawModelId } from '$lib/utils/model-option-id';
+import { SvelteMap, SvelteSet } from 'svelte/reactivity';
+
+/** Grace period before /props is retried for a model after a failed fetch. */
+const PROPS_FETCH_RETRY_COOLDOWN_MS = 30_000;
 
 /**
  * The slice of modelsStore the manager reads. Kept narrow on purpose so it
@@ -29,6 +34,8 @@ import { SvelteSet } from 'svelte/reactivity';
 export interface ModelPropsHost {
 	/** Model rows the manager mirrors fetched modalities onto. */
 	activeModels: ModelOption[];
+	/** Every enabled backend's models, used to resolve a model's owner. */
+	readonly models: ModelOption[];
 	readonly selectedModelName: string | null;
 	readonly loadedModelIds: string[];
 	isModelLoaded(modelId: string): boolean;
@@ -45,6 +52,8 @@ export class ModelPropsManager {
 		maxEntries: MODEL_PROPS_CACHE.MAX_ENTRIES,
 		ttlMs: MODEL_PROPS_CACHE.TTL_MS
 	});
+	/** Last failed /props fetch per model; requests stay on cooldown after it. */
+	private failedPropsAt = new SvelteMap<string, number>();
 	private fetching = new SvelteSet<string>();
 
 	/**
@@ -159,10 +168,25 @@ export class ModelPropsManager {
 
 		if (cached) return cached;
 
+		// never ask a server about a model another backend serves; a name that
+		// exists on two backends resolves to the active one's entry first
+		const option = this.host.models.find(
+			(m) => m.model === modelId || m.id === modelId || rawModelId(m.id) === modelId
+		);
+
+		if (option?.backendId && option.backendId !== backendsStore.active.id) return null;
+
 		if (serverStore.isRouterMode && !this.host.isModelLoaded(modelId)) {
 			return null;
 		}
 
+		// a failing model would otherwise be refetched on every reactive update
+		const failedAt = this.failedPropsAt.get(modelId);
+
+		if (failedAt !== undefined && Date.now() - failedAt < PROPS_FETCH_RETRY_COOLDOWN_MS) {
+			return null;
+		}
+
 		if (this.fetching.has(modelId)) return null;
 
 		this.fetching.add(modelId);
@@ -172,9 +196,11 @@ export class ModelPropsManager {
 
 			this.cache.set(modelId, props);
 			this.cacheVersion++;
+			this.failedPropsAt.delete(modelId);
 
 			return props;
 		} catch (error) {
+			this.failedPropsAt.set(modelId, Date.now());
 			console.warn(`Failed to fetch props for model ${modelId}:`, error);
 
 			return null;